quantum computing

Rounding Almost Commuting Hamiltonians

We show how to efficiently approximate any almost commuting $2$-local qubit Hamiltonian by a commuting one. As a consequence, we show that $\delta$-approximations to the ground energy for $\varepsilon$-almost commuting $2$-local $m$-term qubit Hamiltonians lie in $\mathsf{NP}$ when $\delta \gg m\varepsilon^{1/6}$, extending the classical containment well beyond the commuting setting. Additionally, we present two applications of our rounding framework: Gibbs sampling and fast Hamiltonian simulation for almost commuting systems.

Interactive Oracle Arguments in the QROM and Applications to Succinct Verification of Quantum Computation

This work is motivated by the following question: can an untrusted quantum server convince a classical verifier of the answer to an efficient quantum computation using only polylogarithmic communication? We show how to achieve this in the quantum random oracle model (QROM), after a non-succinct instance-independent setup phase.