Magic-state resource theory for the ground state of the transverse-field Ising model

TL;DR

This paper investigates the behavior of stabilizer Rènyi entropy in the ground state of the transverse-field Ising model, revealing how locality influences quantum complexity and resource requirements across different phases.

Contribution

It introduces a detailed analysis of stabilizer Rènyi entropy in the transverse-field Ising model, highlighting how locality affects quantum resource measures in gapped and critical phases.

Findings

Local stabilizer Rènyi entropy is computable in the gapped phase.

At the critical point, measurements on L spins are needed for accurate entropy estimation.

Error scales as O(L^{-1}) at the critical point.

Abstract

Ground states of quantum many-body systems are both entangled and possess a kind of quantum complexity as their preparation requires universal resources that go beyond the Clifford group and stabilizer states. These resources - sometimes described as magic - are also the crucial ingredient for quantum advantage. We study the behavior of the stabilizer R\'enyi entropy in the integrable transverse field Ising spin chain. We show that the locality of interactions results in a localized stabilizer R\'enyi entropy in the gapped phase thus making this quantity computable in terms of local quantities in the gapped phase, while measurements involving $L$ spins are necessary at the critical point to obtain an error scaling with $O(L^{-1})$.