401 citations · 1.5k across the 17 of their papers we have counts for
17 papers
Diagnostics of mixed-state topological order and breakdown of quantum memory
Ruihua Fan, Yimu Bao, Ehud Altman +1
Topological quantum memory can protect information against local errors up to finite error thresholds. Such thresholds are usually determined based on the success of decoding algor…
Mixed-state topological order and the errorfield double formulation of decoherence-induced transitions
Yimu Bao, Ruihua Fan, Ashvin Vishwanath +1
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 dec…
Generalized Real-space Chern Number Formula and Entanglement Hamiltonian
Ruihua Fan, Pengfei Zhang, Yingfei Gu
We generalize a real-space Chern number formula for gapped free fermions to higher orders. Using the generalized formula, we prove recent proposals for extracting thermal and elect…
Floquet's Refrigerator: Conformal Cooling in Driven Quantum Critical Systems
Xueda Wen, Ruihua Fan, Ashvin Vishwanath
We propose a general method of cooling -- periodic driving generated by spatially deformed Hamiltonians -- and study it in general one-dimensional quantum critical systems describe…
Extracting the Quantum Hall Conductance from a Single Bulk Wavefunction
Ruihua Fan, Rahul Sahay, Ashvin Vishwanath
We propose a new formula that extracts the quantum Hall conductance from a single (2+1)D gapped wavefunction. The formula applies to general many-body systems that conserve particl…
From entanglement generated dynamics to the gravitational anomaly and chiral central charge
Ruihua Fan
We apply modular flow -- entanglement generated dynamics -- to characterize quantum orders of ground state wavefunctions. In particular, we study the linear response of the entangl…
Periodically, Quasi-periodically, and Randomly Driven Conformal Field Theories (II): Furstenberg's Theorem and Exceptions to Heating Phases
Xueda Wen, Yingfei Gu, Ashvin Vishwanath +1
In this sequel (to [Phys. Rev. Res. 3, 023044(2021)], arXiv:2006.10072), we study randomly driven dimensional conformal field theories (CFTs), a family of quantum many-body…
Floquet conformal field theories with generally deformed Hamiltonians
Ruihua Fan, Yingfei Gu, Ashvin Vishwanath +1
In this work, we study non-equilibrium dynamics in Floquet conformal field theories (CFTs) in 1+1D, in which the driving Hamiltonian involves the energy-momentum density spatially…
Periodically, Quasi-periodically, and Randomly Driven Conformal Field Theories: Part I
Xueda Wen, Ruihua Fan, Ashvin Vishwanath +1
In this paper and its sequel, we study non-equilibrium dynamics in driven 1+1D conformal field theories (CFTs) with periodic, quasi-periodic, and random driving. We study a soluble…
Self-Organized Error Correction in Random Unitary Circuits with Measurement
Ruihua Fan, Sagar Vijay, Ashvin Vishwanath +1
Random measurements have been shown to induce a phase transition in an extended quantum system evolving under chaotic unitary dynamics, when the strength of measurements exceeds a…
Emergent Spatial Structure and Entanglement Localization in Floquet Conformal Field Theory
Ruihua Fan, Yingfei Gu, Ashvin Vishwanath +1
We study the energy and entanglement dynamics of D conformal field theories (CFTs) under a Floquet drive with the sine-square deformed (SSD) Hamiltonian. Previous work has s…
Out-of-Time-Order Correlation Functions for Unitary Minimal Models
Ruihua Fan
We analytically study the Out-of-Time-Order Correlation functions (OTOC) for two spatially separated primary operators in two-dimensional unitary minimal models. Besides giving gen…
Competition between Chaotic and Non-Chaotic Phases in a Quadratically Coupled Sachdev-Ye-Kitaev Model
Xin Chen, Ruihua Fan, Yiming Chen +2
The Sachdev-Ye-Kitaev (SYK) model is a concrete solvable model to study non-Fermi liquid properties, holographic duality and maximally chaotic behavior. In this work, we consider a…
Curvature Induced Topological Defects of -wave Superfluid on a Sphere
Ruihua Fan, Pengfei Zhang, Zhe-Yu Shi
We study the ground state of spinless fermions living on a sphere across -wave Feschbach resonances. By construsting a microscopic model of fermions on a general curved surface,…
Measuring out-of-time-order correlators on a nuclear magnetic resonance quantum simulator
Jun Li, Ruihua Fan, Hengyan Wang +5
The idea of the out-of-time-order correlator (OTOC) has recently emerged in the study of both condensed matter systems and gravitational systems. It not only plays a key role in in…
Out-of-Time-Order Correlation at a Quantum Phase Transition
Huitao Shen, Pengfei Zhang, Ruihua Fan +1
In this paper we numerically calculate the out-of-time-order correlation functions in the one-dimensional Bose-Hubbard model. Our study is motivated by the conjecture that a system…
Out-of-Time-Order Correlation for Many-Body Localization
Ruihua Fan, Pengfei Zhang, Huitao Shen +1
In this paper we first compute the out-of-time-order correlators (OTOC) for both a phenomenological model and a random-field XXZ model in the many-body localized phase. We show tha…