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