122 citations · 613 across the 15 of their papers we have counts for
15 papers
Single-ancilla ground state preparation via Lindbladians
Zhiyan Ding, Chi-Fang Chen, Lin Lin
We design a quantum algorithm for ground state preparation in the early fault tolerant regime. As a Monte Carlo-style quantum algorithm, our method features a Lindbladian where the…
Quantum Thermal State Preparation
Chi-Fang Chen, Michael J. Kastoryano, Fernando G. S. L. Brandão +1
Preparing ground states and thermal states is essential for simulating quantum systems on quantum computers. Despite the hope for practical quantum advantage in quantum simulation,…
Speed limits and locality in many-body quantum dynamics
Chi-Fang Chen, Andrew Lucas, Chao Yin
We review the mathematical speed limits on quantum information processing in many-body systems. After the proof of the Lieb-Robinson Theorem in 1972, the past two decades have seen…
Sparse random Hamiltonians are quantumly easy
Chi-Fang, Chen, Alexander M. Dalzell +3
A candidate application for quantum computers is to simulate the low-temperature properties of quantum systems. For this task, there is a well-studied quantum algorithm that perfor…
Fast Thermalization from the Eigenstate Thermalization Hypothesis
Chi-Fang Chen, Fernando G. S. L. Brandão
The Eigenstate Thermalization Hypothesis (ETH) has played a major role in understanding thermodynamic phenomena in closed quantum systems. However, its connection to the timescale…
Average-case Speedup for Product Formulas
Chi-Fang, Chen, Fernando G. S. L. Brandão
Quantum simulation is a promising application of future quantum computers. Product formulas, or Trotterization, are the oldest and still remain an appealing method to simulate quan…
Optimal Frobenius light cone in spin chains with power-law interactions
Chi-Fang Chen, Andrew Lucas
In many-body quantum systems with spatially local interactions, quantum information propagates with a finite velocity, reminiscent of the ``light cone" of relativity. In systems wi…
Concentration of OTOC and Lieb-Robinson velocity in random Hamiltonians
Chi-Fang Chen
The commutator between operators at different space and time has been a diagnostic for locality of unitary evolution. Most existing results are either for specific tractable (rando…
Matrix Product Density Operators: when do they have a local parent Hamiltonian?
Chi-Fang Chen, Kohtaro Kato, Fernando G. S. L. Brandão
We study whether one can write a Matrix Product Density Operator (MPDO) as the Gibbs state of a quasi-local parent Hamiltonian. We conjecture this is the case for generic MPDO and…
Concentration for random product formulas
Chi-Fang Chen, Hsin-Yuan Huang, Richard Kueng +1
Quantum simulation has wide applications in quantum chemistry and physics. Recently, scientists have begun exploring the use of randomized methods for accelerating quantum simulati…
Hierarchy of linear light cones with long-range interactions
Minh C. Tran, Chi-Fang Chen, Adam Ehrenberg +6
In quantum many-body systems with local interactions, quantum information and entanglement cannot spread outside of a linear light cone, which expands at an emergent velocity analo…
Finite speed of quantum scrambling with long range interactions
Chi-Fang Chen, Andrew Lucas
In a locally interacting many-body system, two isolated qubits, separated by a large distance , become correlated and entangled with each other at a time . This finit…
Operator growth bounds from graph theory
Chi-Fang Chen, Andrew Lucas
Let and be local operators in Hamiltonian quantum systems with degrees of freedom and finite-dimensional Hilbert space. We prove that the commutator norm $\lVert [A(t)…
Entanglement Wedge Reconstruction using the Petz Map
Chi-Fang Chen, Geoffrey Penington, Grant Salton
At the heart of recent progress in AdS/CFT is the question of subregion duality, or entanglement wedge reconstruction: which part(s) of the boundary CFT are dual to a given subregi…
Origin of the Drude peak and of zero sound in probe brane holography
Chi-Fang Chen, Andrew Lucas
At zero temperature, the charge current operator appears to be conserved, within linear response, in certain holographic probe brane models of strange metals. At small but finite t…