Learning quantum Hamiltonians at any temperature in polynomial time

Ainesh Bakshi, Allen Liu, Ankur Moitra +1

We study the problem of learning a local quantum Hamiltonian $H$ given copies of its Gibbs state $\rho =e^{-\beta H}/\text{tr}(e^{-\beta H})$ at a known inverse temperature $\beta >0$. Anshu, Arun…