Two component Bose-Hubbard model with higher angular momentum states

We study a Bose-Hubbard Hamiltonian of ultracold two component gas of spinor Chromium atoms. Dipolar interactions of magnetic moments while tuned resonantly by ultralow magnetic field can lead to spin flipping. Due to approximate axial symmetry of individual lattice site, total angular momentum is conserved. Therefore, all changes of the spin are accompanied by the appearance of the angular orbital momentum. This way excited Wannier states with non vanishing angular orbital momentum can be created. Resonant dipolar coupling of the two component Bose gas introduces additional degree of control of the system, and leads to a variety of different stable phases. The phase diagram for small number of particles is discussed.Comment: 4 pages, 2 figure

One-dimensional mixtures of several ultracold atoms: a review

[EN] Recent theoretical and experimental progress on studying one-dimensional systems of bosonic, fermionic, and Bose-Fermi mixtures of a few ultracold atoms confined in traps is reviewed in the broad context of mesoscopic quantum physics. We pay special attention to limiting cases of very strong or very weak interactions and transitions between them. For bosonic mixtures, we describe the developments in systems of three and four atoms as well as different extensions to larger numbers of particles. We also briefly review progress in the case of spinor Bose gases of a few atoms. For fennionic mixtures, we discuss a special role of spin and present a detailed discussion of the two- and three-atom cases. We discuss the advantages and disadvantages of different computation methods applied to systems with intermediate interactions. In the case of very strong repulsion, close to the infinite limit, we discuss approaches based on effective spin chain descriptions. We also report on recent studies on higher-spin mixtures and inter-component attractive forces. For both statistics, we pay particular attention to impurity problems and mass imbalance cases. Finally, we describe the recent advances on trapped Bose-Fermi mixtures, which allow for a theoretical combination of previous concepts, well illustrating the importance of quantum statistics and inter-particle interactions. Lastly, we report on fundamental questions related to the subject which we believe will inspire further theoretical developments and experimental verification.T S acknowledge financial support from the (Polish) National Science Centre with Grant No. 2016/22/E/ST2/00555. MAGM acknowledges funding from the Spanish Ministry MINECO (National Plan15 Grant: FISICATEAMO No. FIS2016-79508-P, SEVERO OCHOA No. SEV-2015-0522, FPI), European Social Fund, Fundacio Cellex, Generalitat de Catalunya (AGAUR Grant No. 2017 SGR 1341 and CERCA/Program), ERC AdG OSYRIS, EU FETPRO QUIC, and the (Polish) National Science Centre, Symfonia Grant No. 2016/20/W/ST4/00314.Sowinski, T.; Garcia March, MA. (2019). One-dimensional mixtures of several ultracold atoms: a review. Reports on Progress in Physics. 82(10):1-44. https://doi.org/10.1088/1361-6633/ab3a80S1448210Pethick, C. J., & Smith, H. (2008). Bose–Einstein Condensation in Dilute Gases. doi:10.1017/cbo9780511802850Lewenstein, M., Sanpera, A., & Ahufinger, V. (2012). Ultracold Atoms in Optical Lattices. doi:10.1093/acprof:oso/9780199573127.001.0001Blume, D. (2010). Jumping from two and three particles to infinitely many. Physics, 3. doi:10.1103/physics.3.74Blume, D. (2012). Few-body physics with ultracold atomic and molecular systems in traps. Reports on Progress in Physics, 75(4), 046401. doi:10.1088/0034-4885/75/4/046401Kinoshita, T. (2004). Observation of a One-Dimensional Tonks-Girardeau Gas. Science, 305(5687), 1125-1128. doi:10.1126/science.1100700Paredes, B., Widera, A., Murg, V., Mandel, O., Fölling, S., Cirac, I., … Bloch, I. (2004). Tonks–Girardeau gas of ultracold atoms in an optical lattice. Nature, 429(6989), 277-281. doi:10.1038/nature02530Kinoshita, T., Wenger, T., & Weiss, D. S. (2005). Local Pair Correlations in One-Dimensional Bose Gases. Physical Review Letters, 95(19). doi:10.1103/physrevlett.95.190406Cheinet, P., Trotzky, S., Feld, M., Schnorrberger, U., Moreno-Cardoner, M., Fölling, S., & Bloch, I. (2008). Counting Atoms Using Interaction Blockade in an Optical Superlattice. Physical Review Letters, 101(9). doi:10.1103/physrevlett.101.090404Will, S., Best, T., Schneider, U., Hackermüller, L., Lühmann, D.-S., & Bloch, I. (2010). Time-resolved observation of coherent multi-body interactions in quantum phase revivals. Nature, 465(7295), 197-201. doi:10.1038/nature09036He, X., Xu, P., Wang, J., & Zhan, M. (2010). High efficient loading of two atoms into a microscopic optical trap by dynamically reshaping the trap with a spatial light modulator. Optics Express, 18(13), 13586. doi:10.1364/oe.18.013586Bourgain, R., Pellegrino, J., Fuhrmanek, A., Sortais, Y. R. P., & Browaeys, A. (2013). Evaporative cooling of a small number of atoms in a single-beam microscopic dipole trap. Physical Review A, 88(2). doi:10.1103/physreva.88.023428Moritz, H., Stöferle, T., Günter, K., Köhl, M., & Esslinger, T. (2005). Confinement Induced Molecules in a 1D Fermi Gas. Physical Review Letters, 94(21). doi:10.1103/physrevlett.94.210401Liao, Y., Rittner, A. S. C., Paprotta, T., Li, W., Partridge, G. B., Hulet, R. G., … Mueller, E. J. (2010). Spin-imbalance in a one-dimensional Fermi gas. Nature, 467(7315), 567-569. doi:10.1038/nature09393Serwane, F., Zurn, G., Lompe, T., Ottenstein, T. B., Wenz, A. N., & Jochim, S. (2011). Deterministic Preparation of a Tunable Few-Fermion System. Science, 332(6027), 336-338. doi:10.1126/science.1201351Wenz, A. N., Zurn, G., Murmann, S., Brouzos, I., Lompe, T., & Jochim, S. (2013). From Few to Many: Observing the Formation of a Fermi Sea One Atom at a Time. Science, 342(6157), 457-460. doi:10.1126/science.1240516Murmann, S., Deuretzbacher, F., Zürn, G., Bjerlin, J., Reimann, S. M., Santos, L., … Jochim, S. (2015). Antiferromagnetic Heisenberg Spin Chain of a Few Cold Atoms in a One-Dimensional Trap. Physical Review Letters, 115(21). doi:10.1103/physrevlett.115.215301Murmann, S., Bergschneider, A., Klinkhamer, V. M., Zürn, G., Lompe, T., & Jochim, S. (2015). Two Fermions in a Double Well: Exploring a Fundamental Building Block of the Hubbard Model. Physical Review Letters, 114(8). doi:10.1103/physrevlett.114.080402McGuire, J. B. (1964). Study of Exactly Soluble One‐Dimensional N‐Body Problems. Journal of Mathematical Physics, 5(5), 622-636. doi:10.1063/1.1704156Zürn, G., Serwane, F., Lompe, T., Wenz, A. N., Ries, M. G., Bohn, J. E., & Jochim, S. (2012). Fermionization of Two Distinguishable Fermions. Physical Review Letters, 108(7). doi:10.1103/physrevlett.108.075303Zürn, G., Wenz, A. N., Murmann, S., Bergschneider, A., Lompe, T., & Jochim, S. (2013). Pairing in Few-Fermion Systems with Attractive Interactions. Physical Review Letters, 111(17). doi:10.1103/physrevlett.111.175302Chuu, C.-S., Schreck, F., Meyrath, T. P., Hanssen, J. L., Price, G. N., & Raizen, M. G. (2005). Direct Observation of Sub-Poissonian Number Statistics in a Degenerate Bose Gas. Physical Review Letters, 95(26). doi:10.1103/physrevlett.95.260403Rontani, M. (2012). Tunneling Theory of Two Interacting Atoms in a Trap. Physical Review Letters, 108(11). doi:10.1103/physrevlett.108.115302Lode, A. U. J., Streltsov, A. I., Sakmann, K., Alon, O. E., & Cederbaum, L. S. (2012). How an interacting many-body system tunnels through a potential barrier to open space. Proceedings of the National Academy of Sciences, 109(34), 13521-13525. doi:10.1073/pnas.1201345109Bloch, I., Dalibard, J., & Zwerger, W. (2008). Many-body physics with ultracold gases. Reviews of Modern Physics, 80(3), 885-964. doi:10.1103/revmodphys.80.885Chin, C., Grimm, R., Julienne, P., & Tiesinga, E. (2010). Feshbach resonances in ultracold gases. Reviews of Modern Physics, 82(2), 1225-1286. doi:10.1103/revmodphys.82.1225Cazalilla, M. A., Citro, R., Giamarchi, T., Orignac, E., & Rigol, M. (2011). One dimensional bosons: From condensed matter systems to ultracold gases. Reviews of Modern Physics, 83(4), 1405-1466. doi:10.1103/revmodphys.83.1405Guan, X.-W., Batchelor, M. T., & Lee, C. (2013). Fermi gases in one dimension: From Bethe ansatz to experiments. Reviews of Modern Physics, 85(4), 1633-1691. doi:10.1103/revmodphys.85.1633Zinner, N. T. (2016). Exploring the few- to many-body crossover using cold atoms in one dimension. EPJ Web of Conferences, 113, 01002. doi:10.1051/epjconf/201611301002Braaten, E., & Hammer, H.-W. (2006). Universality in few-body systems with large scattering length. Physics Reports, 428(5-6), 259-390. doi:10.1016/j.physrep.2006.03.001Naidon, P., & Endo, S. (2017). Efimov physics: a review. Reports on Progress in Physics, 80(5), 056001. doi:10.1088/1361-6633/aa50e8Polkovnikov, A., Sengupta, K., Silva, A., & Vengalattore, M. (2011). Colloquium: Nonequilibrium dynamics of closed interacting quantum systems. Reviews of Modern Physics, 83(3), 863-883. doi:10.1103/revmodphys.83.863Eisert, J., Friesdorf, M., & Gogolin, C. (2015). Quantum many-body systems out of equilibrium. Nature Physics, 11(2), 124-130. doi:10.1038/nphys3215Busch, T., Englert, B.-G., Rzażewski, K., & Wilkens, M. (1998). Foundations of Physics, 28(4), 549-559. doi:10.1023/a:1018705520999WEI, B.-B. (2009). TWO ONE-DIMENSIONAL INTERACTING PARTICLES IN A HARMONIC TRAP. International Journal of Modern Physics B, 23(18), 3709-3715. doi:10.1142/s0217979209053345Olshanii, M. (1998). Atomic Scattering in the Presence of an External Confinement and a Gas of Impenetrable Bosons. Physical Review Letters, 81(5), 938-941. doi:10.1103/physrevlett.81.938Idziaszek, Z., & Calarco, T. (2006). Analytical solutions for the dynamics of two trapped interacting ultracold atoms. Physical Review A, 74(2). doi:10.1103/physreva.74.022712Sowiński, T., Brewczyk, M., Gajda, M., & Rzążewski, K. (2010). Dynamics and decoherence of two cold bosons in a one-dimensional harmonic trap. Physical Review A, 82(5). doi:10.1103/physreva.82.053631Ebert, M., Volosniev, A., & Hammer, H.-W. (2016). Two cold atoms in a time-dependent harmonic trap in one dimension. Annalen der Physik, 528(9-10), 693-704. doi:10.1002/andp.201500365Budewig, L., Mistakidis, S. I., & Schmelcher, P. (2019). Quench dynamics of two one-dimensional harmonically trapped bosons bridging attraction and repulsion. Molecular Physics, 117(15-16), 2043-2057. doi:10.1080/00268976.2019.1575995Sala, S., Zürn, G., Lompe, T., Wenz, A. N., Murmann, S., Serwane, F., … Saenz, A. (2013). Coherent Molecule Formation in Anharmonic Potentials Near Confinement-Induced Resonances. Physical Review Letters, 110(20). doi:10.1103/physrevlett.110.203202Moshinsky, M. (1968). How Good is the Hartree-Fock Approximation. American Journal of Physics, 36(1), 52-53. doi:10.1119/1.1974410Bialynicki-Birula, I. (1985). Exact solutions of nonrelativistic classical and quantum field theory with harmonic forces. Letters in Mathematical Physics, 10(2-3), 189-194. doi:10.1007/bf00398157Załuska-Kotur, M. A., Gajda, M., Orłowski, A., & Mostowski, J. (2000). Soluble model of many interacting quantum particles in a trap. Physical Review A, 61(3). doi:10.1103/physreva.61.033613Ko, Y., & Kim, K. S. (2012). Lifetime of a Nuclear Excited State in Cascade Decay. Few-Body Systems, 54(1-4), 437-440. doi:10.1007/s00601-012-0408-0Klaiman, S., Streltsov, A. I., & Alon, O. E. (2017). Solvable model of a trapped mixture of Bose–Einstein condensates. Chemical Physics, 482, 362-373. doi:10.1016/j.chemphys.2016.07.011Idziaszek, Z., & Calarco, T. (2005). Two atoms in an anisotropic harmonic trap. Physical Review A, 71(5). doi:10.1103/physreva.71.050701Scoquart, T., Seaward, J., Jackson, S. G., & Olshanii, M. (2016). Exactly solvable quantum few-body systems associated with the symmetries of the three-dimensional and four-dimensional icosahedra. SciPost Physics, 1(1). doi:10.21468/scipostphys.1.1.005Olshanii, M., Scoquart, T., Yampolsky, D., Dunjko, V., & Jackson, S. G. (2018). Creating entanglement using integrals of motion. Physical Review A, 97(1). doi:10.1103/physreva.97.013630Gao, B. (1998). Solutions of the Schrödinger equation for an attractive1/r6potential. Physical Review A, 58(3), 1728-1734. doi:10.1103/physreva.58.1728Gao, B. (1999). Repulsive1/r3interaction. Physical Review A, 59(4), 2778-2786. doi:10.1103/physreva.59.2778Kościk, P., & Sowiński, T. (2018). Exactly solvable model of two trapped quantum particles interacting via finite-range soft-core interactions. Scientific Reports, 8(1). doi:10.1038/s41598-017-18505-5Kościk, P., & Sowiński, T. (2019). Exactly solvable model of two interacting Rydberg-dressed atoms confined in a two-dimensional harmonic trap. Scientific Reports, 9(1). doi:10.1038/s41598-019-48442-4Lieb, E. H., & Liniger, W. (1963). Exact Analysis of an Interacting Bose Gas. I. The General Solution and the Ground State. Physical Review, 130(4), 1605-1616. doi:10.1103/physrev.130.1605Lieb, E. H. (1963). Exact Analysis of an Interacting Bose Gas. II. The Excitation Spectrum. Physical Review, 130(4), 1616-1624. doi:10.1103/physrev.130.1616Calogero, F. (1971). Solution of the One‐Dimensional N‐Body Problems with Quadratic and/or Inversely Quadratic Pair Potentials. Journal of Mathematical Physics, 12(3), 419-436. doi:10.1063/1.1665604Sutherland, B. (1971). Quantum Many‐Body Problem in One Dimension: Ground State. Journal of Mathematical Physics, 12(2), 246-250. doi:10.1063/1.1665584Pittman, S. M., Beau, M., Olshanii, M., & del Campo, A. (2017). Truncated Calogero-Sutherland models. Physical Review B, 95(20). doi:10.1103/physrevb.95.205135Marchukov, O. V., & Fischer, U. R. (2019). Self-consistent determination of the many-body state of ultracold bosonic atoms in a one-dimensional harmonic trap. Annals of Physics, 405, 274-288. doi:10.1016/j.aop.2019.03.023Astrakharchik, G. E., Blume, D., Giorgini, S., & Granger, B. E. (2004). Quasi-One-Dimensional Bose Gases with a Large Scattering Length. Physical Review Letters, 92(3). doi:10.1103/physrevlett.92.030402Astrakharchik, G. E., Boronat, J., Casulleras, J., & Giorgini, S. (2005). Beyond the Tonks-Girardeau Gas: Strongly Correlated Regime in Quasi-One-Dimensional Bose Gases. Physical Review Letters, 95(19). doi:10.1103/physrevlett.95.190407Batchelor, M. T., Bortz, M., Guan, X. W., & Oelkers, N. (2005). Evidence for the super Tonks–Girardeau gas. Journal of Statistical Mechanics: Theory and Experiment, 2005(10), L10001-L10001. doi:10.1088/1742-5468/2005/10/l10001Haller, E., Gustavsson, M., Mark, M. J., Danzl, J. G., Hart, R., Pupillo, G., & Nagerl, H.-C. (2009). Realization of an Excited, Strongly Correlated Quantum Gas Phase. Science, 325(5945), 1224-1227. doi:10.1126/science.1175850Cazalilla, M. A., & Ho, A. F. (2003). Instabilities in Binary Mixtures of One-Dimensional Quantum Degenerate Gases. Physical Review Letters, 91(15). doi:10.1103/physrevlett.91.150403Tempfli, E., Zöllner, S., & Schmelcher, P. (2009). Binding between two-component bosons in one dimension. New Journal of Physics, 11(7), 073015. doi:10.1088/1367-2630/11/7/073015Petrov, D. S. (2015). Quantum Mechanical Stabilization of a Collapsing Bose-Bose Mixture. Physical Review Letters, 115(15). doi:10.1103/physrevlett.115.155302Zin, P., Pylak, M., Wasak, T., Gajda, M., & Idziaszek, Z. (2018). Quantum Bose-Bose droplets at a dimensional crossover. Physical Review A, 98(5). doi:10.1103/physreva.98.051603Chiquillo, E. (2018). Equation of state of the one- and three-dimensional Bose-Bose gases. Physical Review A, 97(6). doi:10.1103/physreva.97.063605Cabrera, C. R., Tanzi, L., Sanz, J., Naylor, B., Thomas, P., Cheiney, P., & Tarruell, L. (2017). Quantum liquid droplets in a mixture of Bose-Einstein condensates. Science, 359(6373), 301-304. doi:10.1126/science.aao5686Semeghini, G., Ferioli, G., Masi, L., Mazzinghi, C., Wolswijk, L., Minardi, F., … Fattori, M. (2018). Self-Bound Quantum Droplets of Atomic Mixtures in Free Space. Physical Review Letters, 120(23). doi:10.1103/physrevlett.120.235301Cheiney, P., Cabrera, C. R., Sanz, J., Naylor, B., Tanzi, L., & Tarruell, L. (2018). Bright Soliton to Quantum Droplet Transition in a Mixture of Bose-Einstein Condensates. Physical Review Letters, 120(13). doi:10.1103/physrevlett.120.135301Nishida, Y. (2018). Universal bound states of one-dimensional bosons with two- and three-body attractions. Physical Review A, 97(6). doi:10.1103/physreva.97.061603Pricoupenko, A., & Petrov, D. S. (2018). Dimer-dimer zero crossing and dilute dimerized liquid in a one-dimensional mixture. Physical Review A, 97(6). doi:10.1103/physreva.97.063616Cikojević, V., Markić, L. V., Astrakharchik, G. E., & Boronat, J. (2019). Universality in ultradilute liquid Bose-Bose mixtures. Physical Review A, 99(2). doi:10.1103/physreva.99.023618Parisi, L., Astrakharchik, G. E., & Giorgini, S. (2019). Liquid State of One-Dimensional Bose Mixtures: A Quantum Monte Carlo Study. Physical Review Letters, 122(10). doi:10.1103/physrevlett.122.105302Guijarro, G., Pricoupenko, A., Astrakharchik, G. E., Boronat, J., & Petrov, D. S. (2018). One-dimensional three-boson problem with two- and three-body interactions. Physical Review A, 97(6). doi:10.1103/physreva.97.061605Tiesinga, E., & Johnson, P. R. (2011). Collapse and revival dynamics of number-squeezed superfluids of ultracold atoms in optical lattices. Physical Review A, 83(6). doi:10.1103/physreva.83.063609Silva-Valencia, J., & Souza, A. M. C. (2011). First Mott lobe of bosons with local two- and three-body interactions. Physical Review A, 84(6). doi:10.1103/physreva.84.065601Sowiński, T. (2012). Exact diagonalization of the one-dimensional Bose-Hubbard model with local three-body interactions. Physical Review A, 85(6). doi:10.1103/physreva.85.065601Hincapie-F, A. F., Franco, R., & Silva-Valencia, J. (2016). Mott lobes of theS=1Bose-Hubbard model with three-body interactions. Physical Review A, 94(3). doi:10.1103/physreva.94.033623Dobrzyniecki, J., Li, X., Nielsen, A. E. B., & Sowiński, T. (2018). Effective three-body interactions for bosons in a double-well confinement. Physical Review A, 97(1). doi:10.1103/physreva.97.013609Barranco, M., Guardiola, R., Hernández, S., Mayol, R., Navarro, J., & Pi, M. (2006). Helium Nanodroplets: An Overview. Journal of Low Temperature Physics, 142(1-2), 1-81. doi:10.1007/s10909-005-9267-0Ho, T.-L., & Shenoy, V. B. (1996). Binary Mixtures of Bose Condensates of Alkali Atoms. Physical Review Letters, 77(16), 3276-3279. doi:10.1103/physrevlett.77.3276Myatt, C. J., Burt, E. A., Ghrist, R. W., Cornell, E. A., & Wieman, C. E. (1997). Production of Two Overlapping Bose-Einstein Condensates by Sympathetic Cooling. Physical Review Letters, 78(4), 586-589. doi:10.1103/physrevlett.78.586Esry, B. D., Greene, C. H., Burke, Jr., J. P., & Bohn, J. L. (1997). Hartree-Fock Theory for Double Condensates. Physical Review Letters, 78(19), 3594-3597. doi:10.1103/physrevlett.78.3594Busch, T., Cirac, J. I., Pérez-García, V. M., & Zoller, P. (1997). Stability and collective excitations of a two-component Bose-Einstein condensed gas: A moment approach. Physical Review A, 56(4), 2978-2983. doi:10.1103/physreva.56.2978Ao, P., & Chui, S. T. (1998). Binary Bose-Einstein condensate mixtures in weakly and strongly segregated phases. Physical Review A, 58(6), 4836-4840. doi:10.1103/physreva.58.4836Pu, H., & Bigelow, N. P. (1998). Properties of Two-Species Bose Condensates. Physical Review Letters, 80(6), 1130-1133. doi:10.1103/physrevlett.80.1130Hall, D. S., Matthews, M. R., Ensher, J. R., Wieman, C. E., & Cornell, E. A. (1998). Dynamics of Component Separation in a Binary Mixture of Bose-Einstein Condensates. Physical Review Letters, 81(8), 1539-1542. doi:10.1103/physrevlett.81.1539Gordon, D., & Savage, C. M. (1998). Excitation spectrum and instability of a two-species Bose-Einstein condensate. Physical Review A, 58(2), 1440-1444. doi:10.1103/physreva.58.1440Goldstein, E. V., & Meystre, P. (1997). Quasiparticle instabilities in multicomponent atomic condensates. Physical Review A, 55(4), 2935-2940. doi:10.1103/physreva.55.2935Öhberg, P., & Stenholm, S. (1998). Hartree-Fock treatment of the two-component Bose-Einstein condensate. Physical Review A, 57(2), 1272-1279. doi:10.1103/physreva.57.1272Roy, A., Gautam, S., & Angom, D. (2014). Goldstone modes and bifurcations in phase-separated binary condensates at finite temperature. Physical Review A, 89(1). doi:10.1103/physreva.89.013617Roy, A., & Angom, D. (2015). Thermal suppression of phase separation in condensate mixtures. Physical Review A, 92(1). doi:10.1103/physreva.92.011601Cikojević, V., Markić, L. V., & Boronat, J. (2018). Harmonically trapped Bose–Bose mixtures: a quantum Monte Carlo study. New Journal of Physics, 20(8), 085002. doi:10.1088/1367-2630/aad6ccGirardeau, M. (1960). Relationship between Systems of Impenetrable Bosons and Fermions in One Dimension. Journal of Mathematical Physics, 1(6), 516-523. doi:10.1063/1.1703687Tonks, L. (1936). The Complete Equation of State of One, Two and Three-Dimensional Gases of Hard Elastic Spheres. Physical Review, 50(10), 955-963. doi:10.1103/physrev.50.955Yang, C. N. (1967). Some Exact Results for the Many-Body Problem in one Dimension with Repulsive Delta-Function Interaction. Physical Review Letters, 19(23), 1312-1315. doi:10.1103/physrevlett.19.1312Bethe, H. (1931). Zur Theorie der Metalle. Zeitschrift f�r Physik, 71(3-4), 205-226. doi:10.1007/bf01341708Gaudin, M., & Caux, J.-S. (2009). The Bethe Wavefunction. doi:10.1017/cbo9781107053885Petrov, D. S., Shlyapnikov, G. V., & Walraven, J. T. M. (2000). Regimes of Quantum Degeneracy in Trapped 1D Gases. Physical Review Letters, 85(18), 3745-3749. doi:10.1103/physrevlett.85.3745Dunjko, V., Lorent, V., & Olshanii, M. (2001). Bosons in Cigar-Shaped Traps: Thomas-Fermi Regime, Tonks-Girardeau Regime, and In Between. Physical Review Letters, 86(24), 5413-5416. doi:10.1103/physrevlett.86.5413Girardeau, M. D., & Wright, E. M. (2001). Bose-Fermi Variational Theory of the Bose-Einstein Condensate Crossover to the Tonks Gas. Physical Review Letters, 87(21). doi:10.1103/physrevlett.87.210401Blume, D. (2002). Fermionization of a bosonic gas under highly elongated confinement: A diffusion quantum Monte Carlo study. Physical Review A, 66(5). doi:10.1103/physreva.66.053613Gangardt, D. M., & Shlyapnikov, G. V. (2003). Stability and Phase Coherence of Trapped 1D Bose Gases. Physical Review Letters, 90(1). doi:10.1103/physrevlett.90.010401Kheruntsyan, K. V., Gangardt, D. M., Drummond, P. D., & Shlyapnikov, G. V. (2003). Pair Correlations in a Finite-Temperature 1D Bose Gas. Physical Review Letters, 91(4). doi:10.1103/ph

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