From: Matthew Davis <mdavis_at_physics.uq.edu.au>

Date: Wed, 20 Feb 2008 11:54:29 +1000

Date: Wed, 20 Feb 2008 11:54:29 +1000

The following message was sent to the matts_arxiv list by Matthew Davis <mdavis_at_physics.uq.edu.au>

Hi everyone,

Before I get started, I just thought I would point out to you the "Physics ArXiv

Blog", at www.arxivblog.com. Someone (I don't know who) has got enough time on

their hands every day to summarise a "human interest" paper that has recently

appeared on arXiv.org - I've been looking at it for a few days, and it is pretty

interesting. You can even sign up to receive updates via email (which I have

now done.) Thanks to a subscriber to this list who pointed it out to me (it's

great to get feedback BTW!)

There are 24 new preprints and 18 replacements this week.

------------------------------------------------------------------------------

\\

arXiv:0802.1139

Date: Fri, 8 Feb 2008 13:22:14 GMT (16kb)

Title: Exact number conserving phase-space dynamics of the M-site Bose-Hubbard

model

Authors: F. Trimborn, D. Witthaut, and H. J. Korsch

Categories: quant-ph

Comments: 11 pages, Revtex 4

\\

The dynamics of M-site, N-particle Bose-Hubbard systems is described in

quantum phase space constructed in terms of generalized SU(M) coherent states.

These states have a special significance for these systems as they describe

fully condensed states. Based on the differential algebra developed by Gilmore,

we derive an explicit evolution equation for the (generalized) Husimi-(Q)- and

Glauber-Sudarshan-(P)-distributions. Most remarkably, these evolution equations

turn out to be second order differential equations where the second order terms

scale as 1/N with the particle number. For large N the evolution reduces to a

(classical) Liouvillian dynamics. The phase space approach thus provides a

distinguished instrument to explore the mean-field many-particle crossover. In

addition, the thermodynamic Bloch equation is analyzed using similar

techniques.

\\ ( http://arxiv.org/abs/0802.1139 , 16kb)

------------------------------------------------------------------------------

\\

arXiv:0802.1142

Date: Fri, 8 Feb 2008 13:12:34 GMT (205kb)

Title: The two-mode Bose-Hubbard model revisited: Many-particle and mean-field

evolution in phase space

Authors: F. Trimborn, D. Witthaut, and H. J. Korsch

Categories: quant-ph

Comments: 10 pages, 10 figures, Revtex 4

\\

The number-conserving quantum phase space description of the Bose-Hubbard

model is discussed for the simple but illustrative case of two modes. We

introduce the Husimi-(Q) and the Glauber-Sudarshan-(P)-distribution function

and show that they provide a distinguished tool to analyze many-particle

quantum states. The exact evolution of these distribution functions are given

by second-order partial differential equations, which they provide a

distinguished instrument to derive the celebrated mean-field limit and to go

beyond this approximation. An important consequence is that the applicability

of the mean-field dynamics is greatly enhanced by considering classical phase

space distributions or ensembles instead of single trajectories. Two important

applications of this approach are discussed in detail. For instance this method

cures the well-known breakdown of the mean-field approximation when the

classical dynamics becomes unstable. Furthermore we discuss the heating of a

BEC due to elastic scattering with the background gas which can be understood

simply as phase noise.

\\ ( http://arxiv.org/abs/0802.1142 , 205kb)

------------------------------------------------------------------------------

\\

arXiv:0802.1093

Date: Fri, 8 Feb 2008 05:27:12 GMT (105kb,D)

Title: Ultracold dense gas of deeply bound heteronuclear molecules

Authors: S. Ospelkaus, A. Pe'er, K.-K. Ni, J. J. Zirbel, B. Neyenhuis, S.

Kotochigova, P. S. Julienne, J. Ye, and D. S. Jin

Categories: physics.atom-ph

Comments: 5 pages, 5 figures

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

Recently, the quest for an ultracold and dense ensemble of polar molecules

has attracted strong interest. Polar molecules have bright prospects for novel

quantum gases with long-range and anisotropic interactions, for quantum

information science, and for precision measurements. However, high-density

clouds of ultracold polar molecules have so far not been produced. Here, we

report a key step towards this goal. Starting from an ultracold dense gas of

heteronuclear 40K-87Rb Feshbach molecules with typical binding energies of a

few hundred kHz and a negligible dipole moment, we coherently transfer these

molecules into a vibrational level of the ground-state molecular potential

bound by >10 GHz. We thereby increase the binding energy and the expected

dipole moment of the 40K-87Rb molecules by more than four orders of magnitude

in a single transfer step. Starting with a single initial state prepared with

Feshbach association, we achieve a transfer efficiency of 84%. While dipolar

effects are not yet observable, the presented technique can be extended to

access much more deeply bound vibrational levels and ultimately those

exhibiting a significant dipole moment. The preparation of an ultracold quantum

gas of polar molecules might therefore come within experimental reach.

\\ ( http://arxiv.org/abs/0802.1093 , 105kb)

------------------------------------------------------------------------------

\\

arXiv:0802.1248

Date: Sat, 9 Feb 2008 06:26:06 GMT (228kb)

Title: A nonextensive approach to Bose-Einstein condensation of trapped

interacting boson gas

Authors: A. Lawani (ISMANS), J. Le Meur (ISMANS), D. Tayurskii (ISMANS), A. El

Kaabouchi (ISMANS), L. Nivanen (ISMANS), B. Minisini (ISMANS), F. Tsobnang

(ISMANS), M. Pezeril (ISMANS), A. Le M\'ehaut\'e (ISMANS), Q. A. Wang

(ISMANS)

Categories: cond-mat.stat-mech

Proxy: ccsd hal-00250073

Journal-ref: Journal of Low Temperature Physics 150 (2008) 605-611

DOI: 10.1007/s10909-007-9596-2

\\

In the Bose-Einstein condensation of interacting atoms or molecules such as

87Rb, 23Na and 7Li, the theoretical understanding of the transition temperature

is not always obvious due to the interactions or zero point energy which cannot

be exactly taken into account. The S-wave collision model fails sometimes to

account for the condensation temperatures. In this work, we look at the problem

within the nonextensive statistics which is considered as a possible theory

describing interacting systems. The generalized energy Uq and the particle

number Nq of boson gas are given in terms of the nonextensive parameter q. q>1

(q<1) implies repulsive (attractive) interaction with respect to the perfect

gas. The generalized condensation temperature Tcq is derived versus Tc given by

the perfect gas theory. Thanks to the observed condensation temperatures, we

find q ~ 0.1 for 87Rb atomic gas, q ~ 0.95 for 7Li and q ~ 0.62 for 23Na. It is

concluded that the effective interactions are essentially attractive for the

three considered atoms, which is consistent with the observed temperatures

higher than those predicted by the conventional theory.

\\ ( http://arxiv.org/abs/0802.1248 , 228kb)

------------------------------------------------------------------------------

\\

arXiv:0802.1504

Date: Mon, 11 Feb 2008 19:06:55 GMT (52kb)

Title: Thermodynamics and linear response of a Bose-Einstein condensate of

microcavity polaritons

Authors: Davide Sarchi and Vincenzo Savona

Categories: cond-mat.mes-hall cond-mat.mtrl-sci

Comments: 9 pages, 4 figures

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

In this work we derive a theory of polariton condensation based on the theory

of interacting Bose particles. In particular, we describe self-consistently the

linear exciton-photon coupling and the exciton-nonlinearities, by generalizing

the Hartree-Fock-Popov description of BEC to the case of two coupled Bose

fields at thermal equilibrium. In this way, we compute the density-dependent

one-particle spectrum, the energy occupations and the phase diagram. The

results quantitatively agree with the existing experimental findings. We then

present the equations for the linear response of a polariton condensate and we

predict the spectral response of the system to external optical or mechanical

perturbations.

\\ ( http://arxiv.org/abs/0802.1504 , 52kb)

------------------------------------------------------------------------------

\\

arXiv:0802.1213

Date: Fri, 8 Feb 2008 21:03:14 GMT (899kb,D)

Title: Cold atom confinement in an all-optical dark ring trap

Authors: Spencer E. Olson, Matthew L. Terraciano, Mark Bashkansky, Fredrik K.

Fatemi

Categories: quant-ph

Comments: 5 pages, 4 figures

Journal-ref: Phys. Rev. A 76, 061404(R) (2007)

DOI: 10.1103/PhysRevA.76.061404

License: http://creativecommons.org/licenses/publicdomain/

\\

We demonstrate confinement of $^{85}$Rb atoms in a dark, toroidal optical

trap. We use a spatial light modulator to convert a single blue-detuned

Gaussian laser beam to a superposition of Laguerre-Gaussian modes that forms a

ring-shaped intensity null bounded harmonically in all directions. We measure a

1/e spin-relaxation lifetime of ~1.5 seconds for a trap detuning of 4.0 nm. For

smaller detunings, a time-dependent relaxation rate is observed. We use these

relaxation rate measurements and imaging diagnostics to optimize trap alignment

in a programmable manner with the modulator. The results are compared with

numerical simulations.

\\ ( http://arxiv.org/abs/0802.1213 , 899kb)

------------------------------------------------------------------------------

\\

arXiv:0802.1222

Date: Mon, 11 Feb 2008 18:36:41 GMT (175kb)

Title: S-wave and p-wave scattering in a cold gas of Na and Rb atoms

Authors: H. Ouerdane and M. J. Jamieson

Categories: physics.atom-ph

Comments: 3 pages, 1 table and 2 figures

\\

Using improved experimentally based $X{}1\Sigma^+$ and $a{}3\Sigma^+$

molecular potentials of NaRb, published recently by Pashov {\it et al.} [Phys.

Rev. A {\bf 72}, 062505 (2005)], we apply the variable phase method to compute

new data for low energy scattering of $^{23}$Na atoms by $^{85}$Rb atoms and

$^{87}$Rb atoms. These are scattering lengths and volumes, numbers of bound

states and effective ranges. From an analysis of the contributions of s-wave

and p-wave scatterings to the elastic cross section we estimate temperatures

below which only s-wave scattering is dominant. We supply evidence for the

existence of a near zero energy p-wave bound state supported by the singlet

molecular potential.

\\ ( http://arxiv.org/abs/0802.1222 , 175kb)

------------------------------------------------------------------------------

\\

arXiv:0802.1439

Date: Mon, 11 Feb 2008 13:57:50 GMT (533kb)

Title: Comparison of hyperfine anomalies in the 5S_{1/2} and 6S_{1/2} levels of

^{85}Rb and ^{87}Rb

Authors: A. Perez Galvan (1), Y. Zhao (1), L. A. Orozco (1), E. Gomez (2), A.

D. Lange (2), F. Baumer (2), G. D. Sprouse (2) ((1)Dept. of Physics,

University of Maryland, College Park, MD, U.S.A., (2)Dept. of Physics and

Astronomy, State University of New York at Stony Brook, Stony Brook, NY,

U.S.A.)

Categories: physics.atom-ph

Comments: 9 pages, 3 figures

Journal-ref: Physics Letters B 655 (2007), 114-118

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

We observe a hyperfine anomaly in the measurement of the hyperfine splitting

of the 6S_{1/2} excited level in rubidium. We perform two step spectroscopy

using the 5S_{1/2}->5P_{1/2}->6S_{1/2} excitation sequence. We measure the

splitting of the 6S1/2 level and obtain for the magnetic dipole constants of

^{85}Rb and ^{87}Rb A = 239.18(4) MHz and A=807.66(8) MHz, respectively. The

hyperfine anomaly difference of_{87}delta_{85}=-0.0036(2) comes from the Bohr

Weisskopf effect: a correction to the point interaction between the finite

nuclear magnetization and the electrons, and agrees with that obtained in the

5S_{1/2} ground state.

\\ ( http://arxiv.org/abs/0802.1439 , 533kb)

------------------------------------------------------------------------------

\\

arXiv:0802.1701

Date: Tue, 12 Feb 2008 20:20:10 GMT (212kb)

Title: Breakdown of integrability in a quasi-one-dimensional ultracold bosonic

gas

Authors: I.E. Mazets, T. Schumm, J. Schmiedmayer

Categories: cond-mat.other

Comments: 4 pages, 3 figures, revtex4

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

We demonstrate that virtual excitations of higher radial modes in an atomic

Bose gas in a tightly confining waveguide result in effective three-body

collisions that violate integrability in this quasi-one-dimensional quantum

system and give rise to thermalization. The estimated thermalization rates are

consistent with recent experimental results in quasi-1D dynamics of ultracold

atoms.

\\ ( http://arxiv.org/abs/0802.1701 , 212kb)

------------------------------------------------------------------------------

\\

arXiv:0802.1558

Date: Tue, 12 Feb 2008 03:14:17 GMT (81kb)

Title: Low-frequency vacuum squeezing via polarization self-rotation in Rb

vapor

Authors: Eugeniy E. Mikhailov, Irina Novikova

Categories: quant-ph

Comments: 4 pages, 3 figures

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

We observed squeezed vacuum light at 795 nm in 87Rb vapor via resonant

polarization self-rotation, and report noise sidebands suppression of ~1 dB

below shot noise level spanning from acoustic (30 kHz) to MHz frequencies. This

is the first demonstration of sub-MHz quadrature vacuum squeezing in atomic

systems. The spectral range of observed squeezing matches well typical

bandwidths of electromagnetically induced transparency (EIT) resonances, making

this simple technique for generation of optical fields with non-classical

statistics at atomic transitions wavelengths attractive for EIT-based quantum

information protocols applications.

\\ ( http://arxiv.org/abs/0802.1558 , 81kb)

------------------------------------------------------------------------------

\\

arXiv:0802.1618

Date: Tue, 12 Feb 2008 11:21:39 GMT (18kb)

Title: Coupling of Electronic and Motional Dynamics in a Cold Atom Optical

Lattice

Authors: Hashem Zoubi and Helmut Ritsch

Categories: quant-ph

Comments: 4 pages, 5 figures

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

We study the coupling of internal electronic excitations to vibrational modes

of the external motion of ultracold atoms in an optical lattice. For different

ground and excited state potentials the on-site coupling of excitations and

vibrations term renormalizes the effective electronic transition energy, which

appears e.g. in clock transitions. In addition in the Mott state with filling

factor one, the dipole-dipole coupling between neighbouring sites includes

emission and absorption of vibrational quanta. Such processes create a

significant mechanism for excitation of vibrations leading to motional heating

of the lattice atoms by resonant light interaction. We calculate estimates of

the corresponding parameters from a perturbation expansion in small atomic

displacements.

\\ ( http://arxiv.org/abs/0802.1618 , 18kb)

------------------------------------------------------------------------------

\\

arXiv:0802.1684

Date: Tue, 12 Feb 2008 18:30:15 GMT (123kb)

Title: High-fidelity readout of trapped-ion qubits

Authors: A. Myerson, D. Szwer, S. Webster, D. Allcock, M. Curtis, G. Imreh, J.

Sherman, D. Stacey, A. Steane and D. Lucas

Categories: quant-ph

Comments: 4 pages, 3 figures

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

We demonstrate single-shot qubit readout with fidelity sufficient for

fault-tolerant quantum computation, for two types of qubit stored in single

trapped calcium ions. For an optical qubit stored in the (4S_1/2, 3D_5/2)

levels of 40Ca+ we achieve 99.985(1)% average readout fidelity in one million

trials, using time-resolved photon counting. An adaptive measurement technique

allows 99.98% fidelity to be reached in 225us average detection time. For a

hyperfine qubit stored in the long-lived 4S_1/2 (F=3, F=4) sub-levels of 43Ca+

we propose and implement a simple and robust optical pumping scheme to transfer

the hyperfine qubit to the optical qubit, capable of a theoretical fidelity

99.95% in 10us. Experimentally we achieve 99.77(3)% net readout fidelity,

inferring at least 99.87(4)% fidelity for the transfer operation.

\\ ( http://arxiv.org/abs/0802.1684 , 123kb)

------------------------------------------------------------------------------

\\

arXiv:0802.1688

Date: Tue, 12 Feb 2008 19:02:27 GMT (280kb)

Title: Observation of Ultra-narrow Electromagnetically Induced Transparency and

Slow Light using Purely Electronic Spins in a Hot Atomic Vapor

Authors: F. Goldfarb, J. Ghosh, M. David, J. Ruggiero, T. Chaneli\`ere, J.-L.

Le Gou\"et, H. Gilles, R. Ghosh, and F. Bretenaker

Categories: quant-ph

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

Electromagnetically induced transparency (EIT) is observed in gaseous 4He at

room temperature. Ultra-narrow (less than 10 kHz) EIT windows are obtained for

the first time for purely electronic spins in the presence of Doppler

broadening. The positive role of collisions is emphasized through measurements

of the power dependence of the EIT resonance. Measurement of slow light opens

up possible ways to applications.

\\ ( http://arxiv.org/abs/0802.1688 , 280kb)

------------------------------------------------------------------------------

\\

arXiv:0802.1569

Date: Tue, 12 Feb 2008 06:29:12 GMT (160kb)

Title: p-wave phase shift and scattering length of $^6$Li

Authors: S. Gautam and D. Angom

Categories: physics.atom-ph physics.chem-ph physics.comp-ph

Comments: 10 figures

\\

We have calculated the p-wave phase shifts and scattering length of $^6$Li.

For this we solve the $p$ partial wave Schr\"odinger equation and analyze the

validity of adopting the semiclassical solution to evaluate the constant

factors in the solution. Unlike in the $s$ wave case, the semiclassical

solution does not provide unique value of the constants. We suggest an

approximate analytic solution, which provides reliable results in special

cases. Further more, we also use the variable phase method to evaluate the

phase shifts. The p-wave scattering lengths of $^{132}$Cs and $^{134}$Cs are

calculated to validate the schemes followed. Based on our calculations, the

value of the $p$ wave scattering length of $^6$Li is $-45a_o$.

\\ ( http://arxiv.org/abs/0802.1569 , 160kb)

------------------------------------------------------------------------------

\\

arXiv:0802.1585

Date: Tue, 12 Feb 2008 09:37:45 GMT (735kb)

Title: Experimental Realization of an Optical One-Way Barrier for Neutral Atoms

Authors: Jeremy J. Thorn, Elizabeth A. Schoene, Tao Li, and Daniel A. Steck

Categories: physics.atom-ph

Comments: 5 pages, 4 figures

\\

We demonstrate an asymmetric optical potential barrier for ultracold 87 Rb

atoms using laser light tuned near the D_2 optical transition. Such a one-way

barrier, where atoms impinging on one side are transmitted but reflected from

the other, is a realization of Maxwell's demon and has important implications

for cooling atoms and molecules not amenable to standard laser-cooling

techniques. In our experiment, atoms are confined to a far-detuned dipole trap

consisting of a single focused Gaussian beam, which is divided near the focus

by the barrier. The one-way barrier consists of two focused laser beams

oriented almost normal to the dipole-trap axis. The first beam is tuned to have

a red (blue) detuning from the F=1 -> F' (F=2 -> F') hyperfine transitions, and

thus presents a barrier only for atoms in the F=2 ground state, while letting

F=1 atoms pass. The second beam pumps the atoms to F=2 on the reflecting side

of the barrier, thus producing the asymmetry. We study experimentally the

reflection and transmission dynamics of ultracold atoms in the presence of the

one-way barrier.

\\ ( http://arxiv.org/abs/0802.1585 , 735kb)

------------------------------------------------------------------------------

\\

arXiv:0802.1662

Date: Tue, 12 Feb 2008 16:25:59 GMT (801kb)

Title: Magnetic trapping of atomic nitrogen (14^N) and cotrapping of NH

(X-triplet-Sigma-)

Authors: Matthew T. Hummon, Wesley C. Campbell, Hsin-I Lu, Edem Tsikata, Yihua

Wang, John M. Doyle

Categories: physics.atom-ph

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

We observe magnetic trapping of atomic nitrogen (14^N) and cotrapping of

ground state imidogen (14^NH, X-triplet-Sigma-). Both are loaded directly from

a room temperature beam via buffer gas cooling. We trap approximately 1 * 1011

14^N atoms at a peak density of 5 * 1011 cm-3 at 550 mK. The 12 +5/-3 s 1/e

lifetime of atomic nitrogen in the trap is limited by elastic collisions with

the helium buffer gas. Cotrapping of 14^N and 14^NH is accomplished, with 108

NH trapped molecules at a peak density of 108 cm-3. We observe no spin

relaxation of nitrogen in collisions with helium.

\\ ( http://arxiv.org/abs/0802.1662 , 801kb)

------------------------------------------------------------------------------

\\

arXiv:0802.1793

Date: Wed, 13 Feb 2008 10:24:01 GMT (90kb)

Title: Van Der Waals Revisited

Authors: K. Baerwinkel (U. Osnabrueck), J. Schnack (U. Bielefeld)

Categories: cond-mat.stat-mech

Comments: 11 pages, 4 figures, submitted to Physica A

\\

The van-der-Waals version of the second virial coefficient is not far from

being exact if the model parameters are appropriately chosen. It is shown how

the van-der-Waals resemblance originates from the interplay of thermal

averaging and superposition of scattering phase shift contributions. The

derivation of the two parameters from the quantum virial coefficient reveals a

fermion-boson symmetry in non-ideal quantum gases. Numerical details are worked

out for the Helium quantum gases.

\\ ( http://arxiv.org/abs/0802.1793 , 90kb)

------------------------------------------------------------------------------

\\

arXiv:0802.1821

Date: Wed, 13 Feb 2008 13:10:05 GMT (104kb)

Title: Spontaneous symmetry breaking of gap solitons in double-well traps

Authors: M. Trippenbach, E. Infeld, J. Gocalek, Michal Matuszewski, M.

Oberthaler, and B. A. Malomed

Categories: cond-mat.other

Comments: 6 pages, 5 figures

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

We introduce a two dimensional model for the Bose-Einstein condensate with

both attractive and repulsive nonlinearities. We assume a combination of a

double well potential in one direction, and an optical lattice along the

perpendicular coordinate. We look for dual core solitons in this model,

focusing on their symmetry-breaking bifurcations. The analysis employs a

variational approximation, which is verified by numerical results. The

bifurcation which transforms antisymmetric gap solitons into asymmetric ones is

of supercritical type in the case of repulsion; in the attraction model,

increase of the optical latttice strength leads to a gradual transition from

subcritical bifurcation (for symmetric solitons) to a supercritical one.

\\ ( http://arxiv.org/abs/0802.1821 , 104kb)

------------------------------------------------------------------------------

\\

arXiv:0802.1882

Date: Wed, 13 Feb 2008 18:49:16 GMT (15kb)

Title: Quasiparticles, coherence and nonlinearity: exact simulations of

RF-spectroscopy of strongly interacting one-dimensional Fermi gases

Authors: M. J. Leskinen, V. Apaja, J. Kajala, P. Torma

Categories: cond-mat.supr-con cond-mat.other

Comments: 10 pages, 3 figures

\\

The excitation spectrum of a quantum state can be measured by outcoupling

particles and creating quasiparticles. In ultracold Fermi gases,

RF-spectroscopy realizes such outcoupling. One of the two interacting

(pseudo)spin components is coupled by an RF field to a third component. This

can be viewed as a quasiparticle creation process analogous to tunneling. It

can be also viewed as a coherent rotation in the (pseudo)spin space, analogous

to NMR experiments in superfluid $^{\text{3}}$He. Which picture applies depends

on the coherence of the time evolution. We suggest here that RF-spectroscopy in

ultracold gases provides an interesting crossover between these descriptions

that could be used for studying decoherence in quantum measurement. We compare

the coherent rotation and quasiparticle descriptions, and study nonlinear

effects, by exact simulations of the many-body state and the dynamics in one

dimension. Deviations from linear response are found to suppress pairing

contribution to the RF line shifts in the coherent case.

\\ ( http://arxiv.org/abs/0802.1882 , 15kb)

------------------------------------------------------------------------------

\\

arXiv:0802.1820

Date: Wed, 13 Feb 2008 13:05:15 GMT (424kb)

Title: An empirical investigation of the g-index for 26 physicists in

comparison with the h-index, the A-index, and the R-index

Authors: Michael Schreiber

Categories: physics.soc-ph

Comments: 28 pages, including 4 figures with 6 plots, 4 tables accepted for

publication in J. Am. Soc. Inf. Sci. Techn

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

Hirsch has introduced the h-index to quantify an individual's scientific

research output by the largest number h of a scientist's papers that received

at least h citations. In order to take into account the highly skewed frequency

distribution of citations, Egghe proposed the g-index as an improvement of the

h-index. I have worked out 26 practical cases of physicists from the Institute

of Physics at Chemnitz University of Technology and compare the h and g values.

It is demonstrated that the g-index discriminates better between different

citation patterns. This can also be achieved by evaluating Jin's A-index which

reflects the average number of citations in the h-core and interpreting it in

conjunction with the h-index. h and A can be combined into the R-index to

measure the h-core's citation intensity. I have also determined the A and R

values for the 26 data sets. For a better comparison, I utilize interpolated

indices. The correlations between the various indices as well as with the total

number of papers and the highest citation counts are discussed. The largest

Pearson correlation coefficient is found between g and R. Although the

correlation between g and h is relatively strong, the arrangement of the data

set is significantly different, depending on whether they are put into order

according to the values of either h or g.

\\ ( http://arxiv.org/abs/0802.1820 , 424kb)

------------------------------------------------------------------------------

\\

arXiv:0802.1913

Date: Thu, 14 Feb 2008 15:25:57 GMT (94kb)

Title: One-particle density matrix and momentum distribution function of

one-dimensional anyon gases

Authors: Raoul Santachiara and Pasquale Calabrese

Categories: cond-mat.mes-hall cond-mat.stat-mech

Comments: 21 pages, 4 figures

\\

We present a systematic study of the Green functions of a one-dimensional gas

of impenetrable anyons. We show that the one-particle density matrix is the

determinant of a Toeplitz matrix whose large N asymptotic is given by the

Fisher-Hartwig conjecture. We provide a careful numerical analysis of this

determinant for general values of the anyonic parameter, showing in full

details the crossover between bosons and fermions and the reorganization of the

singularities of the momentum distribution function.

We show that the one-particle density matrix satisfies a Painleve VI

differential equation, that is then used to derive the small distance and large

momentum expansions. We find that the first non-vanishing term in this

expansion is always k^{-4}, that is proved to be true for all couplings in the

Lieb-Liniger anyonic gas and that can be traced back to the presence of a delta

function interaction in the Hamiltonian.

\\ ( http://arxiv.org/abs/0802.1913 , 94kb)

------------------------------------------------------------------------------

\\

arXiv:0802.2002

Date: Thu, 14 Feb 2008 11:30:46 GMT (112kb)

Title: Tightly bound gap solitons in a Fermi gas

Authors: S. K. Adhikari, B. A. Malomed

Categories: cond-mat.other

Comments: 6 pages, 8 figures

Journal-ref: Europhys. Lett. 79 (2007) 50003 (pp1-6)

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

Within the framework of the mean-field-hydrodynamic model of a degenerate

Fermi gas (DFG), we study, by means of numerical methods and variational

approximation (VA), the formation of fundamental gap solitons (FGSs) in a DFG

(or in a BCS superfluid generated by weak interaction between spin-up and

spin-down fermions), which is trapped in a periodic optical-lattice (OL)

potential. An effectively one-dimensional (1D) configuration is considered,

assuming strong transverse confinement; in parallel, a proper 1D model of the

DFG (which amounts to the known quintic equation for the Tonks-Girardeau gas in

the OL) is considered too. The FGSs found in the first two bandgaps of the

OL-induced spectrum (unless they are very close to edges of the gaps) feature a

tightly-bound shape, being essentially confined to a single cell of the OL. In

the second bandgap, we also find antisymmetric tightly-bound subfundamental

solitons (SFSs), with zero at the midpoint. The SFSs are also confined to a

single cell of the OL, but, unlike the FGSs, they are unstable. The predicted

solitons, consisting of $\sim 104 - 105$ atoms, can be created by available

experimental techniques in the DFG of $^6$Li atoms.

\\ ( http://arxiv.org/abs/0802.2002 , 112kb)

------------------------------------------------------------------------------

\\

arXiv:0802.1968

Date: Thu, 14 Feb 2008 07:22:18 GMT (927kb)

Title: Knots in a Spinor Bose-Einstein Condensate

Authors: Yuki Kawaguchi, Muneto Nitta, and Masahito Ueda

Categories: cond-mat.other

Comments: 4 pages, 3 figures

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

We show that knots of spin textures can be created in the polar phase of a

spin-1 Bose-Einstein condensate, and discuss experimental schemes for their

generation and probe, together with their lifetime.

\\ ( http://arxiv.org/abs/0802.1968 , 927kb)

------------------------------------------------------------------------------

\\

arXiv:0802.2083

Date: Thu, 14 Feb 2008 19:12:15 GMT (529kb)

Title: Elastic theory of Normal-Superfluid Boundary in trapped Fermi Gases

Authors: Stefan S. Natu and Erich J. Mueller (Cornell)

Categories: cond-mat.other

Comments: 4 pages, 3 figures (7 subfigures)

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

\\

By modeling the normal-superfluid boundary in a trapped polarized Fermi gas

as an elastic membrane, we calculate the atomic density profile. For small

trapping anisotropy, we find that the superfluid-normal boundary remains

approximately elliptical, and has an aspect ratio different from that of the

trap. For very prolate clouds the boundary becomes distorted into a

capsule-like shape. We present an analytic explanation of this shape.

\\ ( http://arxiv.org/abs/0802.2083 , 529kb)

------------------------------------------------------------------------------

The replacements:

------------------------------------------------------------------------------

\\

arXiv:0709.1899

replaced with revised version Fri, 8 Feb 2008 12:49:09 GMT (58kb)

Title: Yang-Yang thermodynamics on an atom chip

Authors: A.H. van Amerongen, J.J.P. van Es, P. Wicke, K.V. Kheruntsyan, N.J.

van Druten

Categories: cond-mat.other

Comments: extended introduction and conclusions, and minor changes throughout;

accepted for publication in Phys. Rev. Lett

\\ ( http://arxiv.org/abs/0709.1899 , 58kb)

------------------------------------------------------------------------------

\\

arXiv:0801.1874

replaced with revised version Wed, 6 Feb 2008 22:18:19 GMT (290kb)

Title: New Limits on Coupling of Fundamental Constants to Gravity Using

$^{87}$Sr Optical Lattice Clocks

Authors: S. Blatt, A. D. Ludlow, G. K. Campbell, J. W. Thomsen, T. Zelevinsky,

M. M. Boyd, J. Ye, X. Baillard, M. Fouch\'e, R. Le Targat, A. Brusch, P.

Lemonde, M. Takamoto, F.-L. Hong, H. Katori, V. V. Flambaum

Categories: physics.atom-ph physics.gen-ph

Comments: Updated version, corrected sign error, new references. 4 pages, 4

figures

\\ ( http://arxiv.org/abs/0801.1874 , 290kb)

------------------------------------------------------------------------------

\\

arXiv:0709.2273

replaced with revised version Mon, 11 Feb 2008 02:16:05 GMT (308kb)

Title: Multi-component strongly attractive Fermi gas: a color superconductor in

a one-dimensional harmonic trap

Authors: Xia-Ji Liu, Hui Hu and Peter D. Drummond

Categories: cond-mat.supr-con cond-mat.stat-mech

Comments: 14 pages, 9 figures

Journal-ref: Phys. Rev. A 77, 013622 (2008)

\\ ( http://arxiv.org/abs/0709.2273 , 308kb)

------------------------------------------------------------------------------

\\

arXiv:0712.2443

replaced with revised version Sun, 10 Feb 2008 23:04:34 GMT (59kb)

Title: The model of interacting spatial permutations and its relation to the

Bose gas

Authors: Daniel Ueltschi

Categories: cond-mat.stat-mech math-ph math.MP

Comments: 14 pages

\\ ( http://arxiv.org/abs/0712.2443 , 59kb)

------------------------------------------------------------------------------

\\

arXiv:0712.4191

replaced with revised version Sun, 10 Feb 2008 09:31:31 GMT (104kb)

Title: Many-Body Effects on Nonadiabatic Feshbach Conversion in Bosonic Systems

Authors: jie liu, Bin Liu, and Libin Fu

Categories: cond-mat.mes-hall

Comments: 7pages 5figures

\\ ( http://arxiv.org/abs/0712.4191 , 104kb)

------------------------------------------------------------------------------

\\

arXiv:0706.0609

replaced with revised version Mon, 11 Feb 2008 09:04:08 GMT (70kb)

Title: Molecular superfluid phase in systems of one-dimensional multicomponent

fermionic cold atoms

Authors: S. Capponi, G. Roux, P. Lecheminant, P. Azaria, E. Boulat, S. R. White

Categories: cond-mat.str-el

Comments: published version

Journal-ref: Phys. Rev. A 77, 013624 (2008)

DOI: 10.1103/PhysRevA.77.013624

\\ ( http://arxiv.org/abs/0706.0609 , 70kb)

------------------------------------------------------------------------------

\\

arXiv:0710.5444

replaced with revised version Mon, 11 Feb 2008 17:42:56 GMT (62kb)

Title: Light propagation in atomic Mott Insulators

Authors: Francesco Bariani, Iacopo Carusotto

Categories: physics.optics cond-mat.other physics.atom-ph

Journal-ref: Journal of the European Optical Society - Rapid Publications 3,

08005 (2008)

\\ ( http://arxiv.org/abs/0710.5444 , 62kb)

------------------------------------------------------------------------------

\\

arXiv:0704.3114

replaced with revised version Tue, 12 Feb 2008 19:38:07 GMT (629kb)

Title: Topological Winding and Unwinding in Metastable Bose-Einstein

Condensates

Authors: Rina Kanamoto, Lincoln D. Carr, Masahito Ueda

Categories: cond-mat.other

Comments: 4 pages, 3 figures

Journal-ref: Phys. Rev. Lett. 100, 060401 (2008)

\\ ( http://arxiv.org/abs/0704.3114 , 629kb)

------------------------------------------------------------------------------

\\

arXiv:0708.3161

replaced with revised version Tue, 12 Feb 2008 15:43:16 GMT (346kb)

Title: Ground State Properties of an Asymmetric Hubbard Model for Unbalanced

Ultracold Fermionic Quantum Gases

Authors: T. Gottwald and P. G. J. van Dongen

Categories: cond-mat.str-el

Comments: 9 pages, 5 figures

\\ ( http://arxiv.org/abs/0708.3161 , 346kb)

------------------------------------------------------------------------------

\\

arXiv:0712.1677

replaced with revised version Tue, 12 Feb 2008 10:06:24 GMT (430kb)

Title: Quasi-relativistic behavior of cold atoms in light fields

Authors: G. Juzeliunas, J. Ruseckas, M. Lindberg, L. Santos and P. Ohberg

Categories: cond-mat.mes-hall physics.atom-ph quant-ph

Comments: 4 pages, updated version, Phys. Rev. A 77, (R)011802 (2008)

\\ ( http://arxiv.org/abs/0712.1677 , 430kb)

------------------------------------------------------------------------------

\\

arXiv:0707.1653

replaced with revised version Tue, 12 Feb 2008 15:33:08 GMT (93kb)

Title: Dynamical instability in kicked Bose-Einstein condensates: Bogoliubov

resonances

Authors: J. Reslen, C.E. Creffield, and T.S. Monteiro

Categories: quant-ph

Comments: 8 pages

\\ ( http://arxiv.org/abs/0707.1653 , 93kb)

------------------------------------------------------------------------------

\\

arXiv:0711.4418

replaced with revised version Tue, 12 Feb 2008 03:12:29 GMT (161kb)

Title: A pumped atom laser

Authors: N. P. Robins, C. Figl, M. Jeppesen, G. R. Dennis and J. D. Close

Categories: physics.atom-ph

Comments: Version 2 contains 18 pages and 4 figures. We have significantly

rewritten the introduction, as well as including a discussion of Rayleigh and

Raman superradiant scattering and how these relate to continuous pumping of

an atom laser. Five new references were added

\\ ( http://arxiv.org/abs/0711.4418 , 161kb)

------------------------------------------------------------------------------

\\

arXiv:0801.3999

replaced with revised version Tue, 12 Feb 2008 12:54:44 GMT (845kb)

Title: Rabi oscillations between ground and Rydberg states and van der Waals

blockade in a mesoscopic frozen Rydberg gas

Authors: Markus Reetz-Lamour, Johannes Deiglmayr, Thomas Amthor and Matthias

Weidem\"uller

Categories: physics.atom-ph

\\ ( http://arxiv.org/abs/0801.3999 , 845kb)

-----------------------------------------------------------------------------

\\

arXiv:cond-mat/0604619

replaced with revised version Tue, 12 Feb 2008 22:07:02 GMT (601kb)

Title: Designing potentials by sculpturing wires

Authors: Leonardo Della Pietra, Simon Aigner, Christoph vom Hagen, S\"onke

Groth, Israel Bar-Joseph, Henri J.Lezec, J\"org Schmiedmayer

Categories: cond-mat.mtrl-sci quant-ph

Comments: 6 pages, 8 figures

Journal-ref: Phys. Rev. A 75, 063604 (2007)

\\ ( http://arxiv.org/abs/cond-mat/0604619 , 601kb)

------------------------------------------------------------------------------

\\

arXiv:0706.2826

replaced with revised version Wed, 13 Feb 2008 15:04:13 GMT (110kb)

Title: Barrier transmission for the one-dimensional nonlinear Schr\"odinger

equation: resonances and transmission profiles

Authors: K. Rapedius, H. J. Korsch

Categories: cond-mat.other

Comments: 9 pages, 6 figures, 1 table

\\ ( http://arxiv.org/abs/0706.2826 , 110kb)

------------------------------------------------------------------------------

\\

arXiv:0712.4073

replaced with revised version Wed, 13 Feb 2008 15:16:07 GMT (664kb)

Title: Quantum Phases of Trapped Ions in an Optical Lattice

Authors: Roman Schmied, Tommaso Roscilde, Valentin Murg, Diego Porras, J.

Ignacio Cirac

Categories: cond-mat.str-el

Comments: re-formatted; added discussion of feasibility

\\ ( http://arxiv.org/abs/0712.4073 , 664kb)

------------------------------------------------------------------------------

\\

arXiv:0709.3740

replaced with revised version Thu, 14 Feb 2008 18:52:11 GMT (565kb)

Title: Staggered-Vortex Superfluid of Ultracold Bosons in an Optical Lattice

Authors: Lih-King Lim, C. Morais Smith, Andreas Hemmerich

Categories: cond-mat.supr-con cond-mat.other

Comments: 4 pages, 4 figures

\\ ( http://arxiv.org/abs/0709.3740 , 565kb)

------------------------------------------------------------------------------

\\

arXiv:0710.5187

replaced with revised version Thu, 14 Feb 2008 19:44:03 GMT (524kb)

Title: Phase Coherence and Superfluid-Insulator Transition in a Disordered

Bose-Einstein Condensate

Authors: Yong P. Chen, J. Hitchcock, D. Dries, M. Junker, C. Welford, R. G.

Hulet

Categories: cond-mat.other

Comments: 4 pages, 5 figures

\\ ( http://arxiv.org/abs/0710.5187 , 524kb)

------------------------------------------------------------------------------

Have a great week everyone,

Matt.

-- ========================================================================= Dr M. J. Davis, Senior Lecturer in Physics School of Physical Sciences, email: mdavis_at_physics.uq.edu.au University of Queensland, ph : +61 7 334 69824 Brisbane, QLD 4072, fax : +61 7 336 51242 Australia. http://www.physics.uq.edu.au/people/mdavis/ ========================================================================= Matt's arXiv selection: weekly summary of cold-atom papers from arXiv.org http://www.physics.uq.edu.au/people/mdavis/matts_arXiv/ ========================================================================= Legal stuff: Unless stated otherwise, this e-mail represents only the views of the sender and not the views of the University of Queensland =========================================================================Received on Wed Feb 20 2008 - 13:54:10 EST

*
This archive was generated by hypermail 2.2.0
: Thu May 08 2008 - 11:51:41 EST
*