The universal equation of state of a unitary fermionic gas

Universal Spectral Correlations in Orthogonal-Unitary and Symplectic-Unitary Crossover Ensembles of Random Matrices

Orthogonal - unitary and symplectic - unitary crossover ensembles of random matrices are relevant in many contexts, especially in the study of time reversal symmetry breaking in quantum chaotic systems. Using skew-orthogonal polynomials we show that the same generic form of n-level correlation functions are obtained for the Jacobi family of crossover ensembles, including the Laguerre and Gaussian cases. For large matrices we find universal forms of unfolded correlation functions when expressed in terms of a rescaled transition parameter with arbitrary initial level density.

从混合费米子高斯态中通过纠缠投影熵提取普适纠缠标度

Extracting Universal Entanglement Scaling from Mixed Fermionic Gaussian States via Entanglement Projected Entropy

本文引入纠缠投影熵，通过从混合费米子高斯态中提取边界敏感的量子关联，恢复零温共形标度并揭示有限温度普适标度。

Average eigenstate entanglement entropy of the XY chain in a transverse field and its universality for translationally invariant quadratic fermionic models

We recently showed [Phys. Rev. Lett. 121, 220602 (2018)] that the average bipartite entanglement entropy of all energy eigenstates of the quantum Ising chain exhibits a universal (for translationally invariant quadratic fermionic models) leading term that scales linearly with the subsystem's volume, while in the thermodynamic limit the first subleading correction does not vanish at the critical field (it only depends on the ratio $f$ between the volume of the subsystem and volume of the system) and vanishes otherwise. Here we show, analytically for bounds and numerically for averages, that the…

多体费米子非高斯性的普适界与相变

Universal Bound and Phase Transition in Many-Body Fermionic Non-Gaussianity

本研究推导了费米子非高斯性的普适上界，并发现Sachdev-Ye-Kitaev哈密顿量演化下MRE密度出现一阶相变，伴随置换对称性自发破缺。

Unitary matrix models and random partitions: Universality and multi-criticality

The generating functions for the gauge theory observables are often represented in terms of the unitary matrix integrals. In this work, the perturbative and non-perturbative aspects of the generic multi-critical unitary matrix models are studied by adopting the integrable operator formalism, and the multi-critical generalization of the Tracy--Widom distribution in the context of random partitions. We obtain the universal results for the multi-critical model in the weak and strong coupling phases. The free energy of the instanton sector in the weak coupling regime, and the genus expansion of th…

Thermodynamics of a Trapped Unitary Fermi Gas

We present the first model-independent comparison of recent measurements of the entropy and of the critical temperature of a unitary Fermi gas, performed by Luo et al., with the most complete results currently available from finite temperature Monte Carlo calculations. The measurement of the critical temperature in a cold fermionic atomic cloud is consistent with a value $T_c=0.23(2)epsilon_F$ in the bulk, as predicted by the present authors in their Monte Carlo calculations.

费米子焦耳-汤姆逊效应的观测

Observation of the Fermionic Joule-Thomson Effect

本研究在理想与幺正费米气体中观测到量子焦耳-汤姆逊效应，验证了标度不变系统下稀疏化过程与JT节流的热力学等效性，揭示了量子统计力与粒子间相互作用对JT加热的调控作用。