9 papers
Efficient and simple Gibbs state preparation of the 2D toric code via duality to classical Ising chains
Pablo Páez-Velasco, Niclas Schilling, Samuel O. Scalet +2
We introduce the notion of polynomial-depth duality transformations, which relates two sets of operator algebras through a conjugation by a poly-depth quantum circuit, and make use…
Dissipative microcanonical ensemble preparation from KMS-detailed balance
Anirban N. Chowdhury, Samuel O. Scalet, Kunal Sharma
Stationary states of quantum many-body Hamiltonians are invariant under the Hamiltonian evolution. Besides ground and thermal states, this class includes microcanonical ensembles t…
Spatial Entanglement Sudden Death in Spin Chains at All Temperatures
Samuel O. Scalet
We prove a finite entanglement length for the Gibbs state of any local Hamiltonian on a spin chain at any finite temperature: After removing an interval of size at least equal to t…
Classical Estimation of the Free Energy and Quantum Gibbs Sampling from the Markov Entropy Decomposition
Samuel O. Scalet, Angela Capel, Anirban N. Chowdhury +4
We revisit the Markov Entropy Decomposition, a classical convex relaxation algorithm introduced by Poulin and Hastings to approximate the free energy in quantum spin lattices. We i…
Convergence of the Cumulant Expansion and Polynomial-Time Algorithm for Weakly Interacting Fermions
Hongrui Chen, Cambyse Rouzé, Jielun Chen +6
We propose a randomized algorithm to compute the log-partition function of weakly interacting fermions with polynomial runtime in both the system size and precision. Although weakl…
Conditional Independence of 1D Gibbs States with Applications to Efficient Learning
Ãlvaro M. Alhambra, Ãngela Capel, Paul Gondolf +2
We show that spin chains in thermal equilibrium have a correlation structure in which individual regions are strongly correlated at most with their near vicinity. We quantify this…