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arXiv 1609.01702cond-mat.quant-gashep-latnucl-th
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具有吸引相互作用的一维SU(4)和SU(6)费米子的热力学

Thermodynamics of one-dimensional SU(4) and SU(6) fermions with attractive interactions

M. D. Hoffman, A. C. Loheac, W. J. Porter, J. E. Drut

摘要:

受多自由度超冷原子操纵和探测研究进展的启发,我们提出了一种有限温度格子Monte Carlo方法,计算了一维SU(4)和SU(6)对称费米子系统的密度和压力状态方程以及Tan接触.我们还提供了一个普适关系的非微扰证明,即在SU(2)情况下可计算的量完全确定SU($N_f$)情况下的维里系数。这些一维系统之所以吸引人,是因为它们可以在高度约束的陷阱中通过实验实现,并且因为相关性所起的主导作用。后者通常是非微扰的,对于理解基态和量子相变至关重要。虽然在任何有限温度下,一维和二维的量子涨落通常被热涨落所压倒,但我们发现量子效应确实在热力学量中留下了印记。我们的计算表明,相对于SU(2)情形,额外的自由度在$βμ$消失的大范围内提供了密度和压力的显著增强(以它们的非相互作用对应物为单位),其中$β$是逆温度,$μ$是化学势。正如最近的实验所示,我们在这里探索的热力学可以在高度约束的陷阱和光晶格中以受控和精确的方式测量。我们的结果是一个预测这样的实验在一维与原子的高核自旋。

英文摘要:

Motivated by advances in the manipulation and detection of ultracold atoms with multiple internal degrees of freedom, we present a finite-temperature lattice Monte Carlo calculation of the density and pressure equations of state, as well as Tan's contact, of attractively interacting SU(4)- and SU(6)-symmetric fermion systems in one spatial dimension. We also furnish a nonperturbative proof of a universal relation whereby quantities computable in the SU(2) case completely determine the virial coefficients of the SU($N_f$) case. These one-dimensional systems are appealing because they can be experimentally realized in highly constrained traps and because of the dominant role played by correlations. The latter are typically nonperturbative and are crucial for understanding ground states and quantum phase transitions. While quantum fluctuations are typically overpowered by thermal ones in one and two dimensions at any finite temperature, we find that quantum effects do leave their imprint in thermodynamic quantities. Our calculations show that the additional degrees of freedom, relative to the SU(2) case, provide a dramatic enhancement of the density and pressure (in units of their noninteracting counterparts) in a wide region around vanishing $βμ$, where $β$ is the inverse temperature and $μ$ the chemical potential. As shown recently in experiments, the thermodynamics we explore here can be measured in a controlled and precise fashion in highly constrained traps and optical lattices. Our results are a prediction for such experiments in one dimension with atoms of high nuclear spin.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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