Professional Education

  • Doctor of Philosophy, University of California Berkeley (2023)
  • BSc, Peking University, Physics (2017)

Stanford Advisors

Contact

  • Academic
    yimu@stanford.edu
    University - Scholar Department: Physics Position: Postdoctoral Scholar

Additional Info

Links

Current Research and Scholarly Interests

I am a theoretical physicist working at the intersection of condensed matter physics and quantum information science. My research explores the many-body aspects of quantum information and novel collective phenomena both in and out of equilibrium using various analytical and numerical methods. A few specific recent interests include quantum error correction, mixed-state topological phases, and numerical and analytical methods based on tensor network formulations.

All Publications

  • Mixed-State Topological Order and the Errorfield Double Formulation of Decoherence-Induced Transitions PHYSICAL REVIEW LETTERS Bao, Y., Fan, R., Vishwanath, A., Altman, E. 2026; 136 (22): 220402

    Abstract

    We develop an effective field theory characterizing the impact of decoherence on states with Abelian topological order and on their capacity to protect quantum information. The decoherence appears as a temporal defect in the double topological quantum field theory that describes the pure density matrix of the uncorrupted state, and it drives a boundary phase transition involving anyon condensation at a critical coupling strength. The ensuing decoherence-induced phases and the loss of quantum information are classified by the Lagrangian subgroups of the double topological order. Our framework generalizes the error recovery transitions, previously derived for certain stabilizer codes, to generic topologically ordered states and shows that they stem from phase transitions in the intrinsic topological order characterizing the mixed state.

    View details for DOI 10.1103/6f98-tvb8

    View details for Web of Science ID 001795253300008

    View details for PubMedID 42330447

  • Quantum Error Correction in Scrambling Dynamics and Measurement-Induced Phase Transition. Physical review letters Choi, S., Bao, Y., Qi, X. L., Altman, E. 2020; 125 (3): 030505

    Abstract

    We analyze the dynamics of entanglement entropy in a generic quantum many-body open system from the perspective of quantum information and error corrections. We introduce a random unitary circuit model with intermittent projective measurements, in which the degree of information scrambling by the unitary and the rate of projective measurements are independently controlled. This model displays two stable phases, characterized by the volume-law and area-law scaling entanglement entropy in steady states. The transition between the two phases is understood from the point of view of quantum error correction: the chaotic unitary evolution protects quantum information from projective measurements that act as errors. A phase transition occurs when the rate of errors exceeds a threshold that depends on the degree of information scrambling. We confirm these results using numerical simulations and obtain the phase diagram of our model. Our work shows that information scrambling plays a crucial role in understanding the dynamics of entanglement in an open quantum system and relates the entanglement phase transition to changes in quantum channel capacity.

    View details for DOI 10.1103/PhysRevLett.125.030505

    View details for PubMedID 32745425

https://orcid.org/0000-0002-5357-8821