KITS-IOP-ITP Joint Seminar
Title: Entanglement of Many-Body Mixed States
Speaker: Prof. Xiao Yan Xu (Shanghai Jiao Tong University)
Time: 15:00, April 25 (Thursday) 2024
Place: Rm M830, IOP-CAS
Abstract:
Many-body entanglement unveils additional aspects of quantum matter and offers insights into strongly correlated physics. While ground-state entanglement has received much attention in the past decade, the study of mixed-state quantum entanglement using negativity in interacting fermionic systems remains less explored. We demonstrate that the partially transposed density matrix of interacting fermions, similar to the reduced density matrix, can be expressed as a weighted sum of Gaussian states describing free fermions, enabling the calculation of rank-n Rényi negativity within the determinantal quantum Monte Carlo framework. We conduct the first calculation of rank-two Rényi negativity for the half-filled Hubbard model and the spinless t-V model and find that the area law coefficient of the Rényi negativity has a singularity at the finite-temperature transition point. Our work contributes to the calculation of entanglement and sets the stage for future studies on quantum entanglement in various fermionic many-body mixed states.
More details can be found in http://seminar.cpsjournals.cn/
Title: Quantum Phases in Semiconductor Moire Superlattices
Speaker: Prof. Fengcheng Wu (Wuhan University)
Time: 10:00, April 26 (Friday) 2024
Place: Rm M830, IOP-CAS
Abstract:
Moire superlattices formed by two-dimensional semiconductors of transition metal dichalcogenides (e.g., WSe2 and MoTe2 ) have become an important platform for studying novel quantum phases arising from strong correlation and/or topological effects. Quantum phases observed in semiconductor moire superlattices include Mott insulators, generalized Wigner crystals, integer, and fractional quantum anomalous Hall insulators, as well as integer and fractional quantum spin Hall insulators. In this talk, I will review theoretical and experimental developments in this field, including our theoretical work on the interaction-driven topological phase diagram in twisted bilayer MoTe2.
About Speaker: Fengcheng Wu is a Professor in the School of Physics and Technology at Wuhan University. He received his BSc in Physics from University of Science and Technology of China in 2011 and PhD in physics from University of Texas at Austin in 2016. He performed postdoc research at Argonne National Laboratory (2016-2018) and University of Maryland (2018-2020). His research is on condensed matter theory, with a focus on low-dimensional quantum physics.
More details can be found in http://seminar.cpsjournals.cn/