Unravelling Quantum Dot Array Simulators via Singlet-Triplet Measurements

TL;DR

This paper investigates how singlet-triplet measurements in quantum dot arrays can be used to probe, discriminate, and explore quantum many-body states and phase transitions in Heisenberg spin chains, with applications in entanglement generation.

Contribution

It introduces an efficient protocol for ground-state discrimination and phase transition exploration in quantum dot simulators using singlet-triplet measurements, considering realistic noise effects.

Findings

Effective ground-state discrimination protocol developed

Phase transitions in frustrated spin chains can be systematically studied

Long-distance entanglement can be heralded between quantum dots

Abstract

Recently, singlet-triplet measurements in double dots have emerged as a powerful tool in quantum information processing. In parallel, quantum dot arrays are being envisaged as analog quantum simulators of many-body models. Thus motivated, we explore the potential of the above singlet-triplet measurements for probing and exploiting the ground-state of a Heisenberg spin chain in such a quantum simulator. We formulate an efficient protocol to discriminate the achieved many-body ground-state with other likely states. Moreover, the transition between quantum phases, arising from the addition of frustrations in a $J_1-J_2$ model, can be systematically explored using the same set of measurements. We show that the proposed measurements have an application in producing long distance heralded entanglement between well separated quantum dots. Relevant noise sources, such as non-zero temperatures and nuclear spin interactions, are considered.