Kao Group

New Preprint

2022-06-10T00:00:00+00:00

New preprint by Yun-Chung is available at arXiv!

CProtected Gapless Edge States In Trivial Topology

Authors: Yun-Chung Chen, Yu-Ping Lin, Ying-Jer Kao

Abstract:Bulk-boundary correspondence serves as an important feature of the strong topological insulators, including Chern insulators and Z2 topological insulators. Under nontrivial band topology, the protected gapless edge states correspond to the Wannier obstruction or Wilson-loop winding in the bulk. Recent studies show that the bulk topological features may not imply the existence of protected gapless edge states. Here we address the opposite question: Does the existence of protected gapless edge states necessarily imply the Wannier obstruction or Wilson-loop winding? We provide an example where the protected gapless edge states arise without the aforementioned bulk topological features. This trivialized topological insulator belongs to a new class of systems with non-delta-like Wannier functions. Interestingly, the gapless edge states are not protected by the crystalline symmetry; instead the protection originates from the mirror antisymmetry, a combination of chiral and mirror symmetries. Although the protected gapless edge states cannot be captured by the bulk topological features, they can be characterized by the spectral flow in the entanglement spectrum.

arXiv:2206.04858

Paper Published

2020-09-30T00:00:00+00:00

Paper with Kai-Hsin Wu is published in Phys. Rev. Lett. 125, 140603 (2020)

Entanglement Renyi Negativity across a Finite Temperature Transition: A Monte Carlo Study

New Member

2020-08-01T00:00:00+00:00

We welcome a new group member David Lin and Yu-Hsueh Chen !!!

Paper Published

2020-04-16T00:00:00+00:00

New paper with Wen-Han Kao is published in Phys. Rev. Research 2, 023046 (2020)

Emergent snake magnetic domains in canted kagome ice

Paper Published

2019-09-18T00:00:00+00:00

New paper with Adil A. Gangat is published in Phys. Rev. B 100, 094430 (2019)

Phase boundary location with information-theoretic entropy in tensor renormalization group flows

New Member

2019-08-01T00:00:00+00:00

We welcome a new group member Dr. Jozef Genzor !!!

Paper Published

2019-06-05T00:00:00+00:00

New paper with Kai-Wen Zhao, Wen-Han Kao, and Kai-Hsin Wu is published in Phys. Rev. E 99, 062106 (2019)

Generation of ice states through deep reinforcement learning

Paper Published

2019-04-29T00:00:00+00:00

New paper with Kai-Hsin Wu and Yi-Ping Huang (MPIPKS) is published in Phys. Rev. B 99, 134440 (2019)

Tunneling-induced restoration of classical degeneracy in quantum kagome ice

New Preprint

2019-03-17T00:00:00+00:00

New preprint with Kai-Wen Zhao, Wen-Han Kao and Kai-Hsin Wu on Generation of ice states through deep reinforcement learning is now available on the arXiv:1903.04698.

Generation of ice states through deep reinforcement learning

Authors: Kai-Wen Zhao, Wen-Han Kao, Kai-Hsin Wu, Ying-Jer Kao

We present a deep reinforcement learning framework where a machine agent is trained to search for a policy to generate a ground state for the square ice model by exploring the physical environment. After training, the agent is capable of proposing a sequence of local moves to achieve the goal. Analysis of the trained policy and the state value function indicates that the ice rule and loop-closing condition are learned without prior knowledge. We test the trained policy as a sampler in the Markov chain Monte Carlo and benchmark against the baseline loop algorithm. This framework can be generalized to other models with topological constraints where generation of constraint-preserving states is difficult.

Talk At Kitp

2019-02-08T00:00:00+00:00

Prof. Kao gave a talk on Generation of topologically constrained states through deep reinforcement learning.

Talk available http://online.kitp.ucsb.edu/online/machine19/kao/