2018/06/30 by Xunda Jiang, Shuyuan Wu, Qinzhou Ye +1
Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Binary number #Cold Atom Physics and Bose-Einstein Condensates #Critical exponent #Critical phenomena #Excitation #Exponent #Quantum many-body systems #Scaling #Spectral line #Superfluidity #Universality (dynamical systems) #cond-mat.quant-gas
paper · pdf · doi:10.1088/1367-2630/ab00bf
13 pages, 5 figures
openalex created_date 2018/06/13 · arxiv created 2018/10/09 · openalex publication_date 2019/01/23 · arxiv updated 2019/03/27 · openalex updated_date 2026/08/05
We investigate the non-equilibrium dynamics across the miscible–immiscible phase separation in a binary mixture of Bose–Einstein condensates. The excitation spectra reveal that the Landau critical velocity vanishes at the critical point, where the superfluidity spontaneously breaks down. We analytically extract the dynamical critical exponent z = 2 and static correlation length critical exponent v = 1/2 from the Landau critical velocity. Moreover, by simulating the real-time dynamics across the critical point, we find the average domain number and the average bifurcation delay show universal scaling laws with respect to the quench time. We then numerically extract the static correlation length critical exponent v = 1/2 and the dynamical critical exponent z = 2 according to Kibble–Zurek mechanism. The scaling exponents ( v = 1/2, z = 2) in the phase separation driven by quenching the atom–atom interaction are different from the ones ( v = 1/2, z = 1) in the phase separation driven by quenching the Rabi coupling strength (2009 Phys. Rev. Lett. 102 070401; 2011 Phys. Rev. Lett. 107 230402). Our study explores the connections between the spontaneous superfluidity breakdown and the spontaneous defect formation in the phase separation dynamics.