Simulating dirty bosons on a quantum computer

TL;DR

This paper explores how quantum computers can simulate dirty bosons, revealing the effects of disorder, interactions, and hardware noise on quantum phase transitions in one and two dimensions.

Contribution

It introduces methods for simulating dirty bosons on quantum computers, including adiabatic state preparation and noise analysis, applicable to current and future quantum hardware.

Findings

Quantum circuits can be compressed for 1D simulations on current hardware.

Large-scale classical simulations are needed for 2D due to circuit complexity.

Noise affects localized and delocalized phases differently, with scaling laws governing these effects.

Abstract

The physics of dirty bosons highlights the intriguing interplay of disorder and interactions in quantum systems, playing a central role in describing, for instance, ultracold gases in a random potential, doped quantum magnets, and amorphous superconductors. Here, we demonstrate how quantum computers can be used to elucidate the physics of dirty bosons in one and two dimensions. Specifically, we explore the disorder-induced delocalized-to-localized transition using adiabatic state preparation. In one dimension, the quantum circuits can be compressed to small enough depths for execution on currently available quantum computers. In two dimensions, the compression scheme is no longer applicable, thereby requiring the use of large-scale classical state vector simulations to emulate quantum computer performance. In addition, simulating interacting bosons via emulation of a noisy quantum computer allowed us to study the effect of quantum hardware noise on the physical properties of the simulated system. Our results suggest that scaling laws control how noise modifies observables versus its strength, the circuit depth, and the number of qubits. Moreover, we observe that noise impacts the delocalized and localized phases differently. A better understanding of how noise alters the genuine properties of the simulated system is essential for leveraging noisy intermediate-scale quantum devices for simulation of dirty bosons, and indeed for condensed matter systems in general.