Quantum criticality using a superconducting quantum processor

TL;DR

This paper demonstrates how noisy intermediate-scale quantum (NISQ) devices can be used to study quantum criticality, revealing how noise influences critical properties and introducing modified scaling laws to account for hardware imperfections.

Contribution

It introduces a noise model for NISQ devices, verifies modified scaling laws for quantum criticality, and shows how hardware imperfections can be systematically incorporated into physical property extraction.

Findings

Noise induces a new length scale similar to temperature.

Modified scaling laws successfully account for hardware noise.

Experimental data aligns with the noise model predictions.

Abstract

Quantum criticality emerges from the collective behavior of many interacting quantum particles, often at the transition between different phases of matter. It is one of the cornerstones of condensed matter physics, which we access on noisy intermediate-scale (NISQ) quantum devices by leveraging a dynamically driven phenomenon. We probe the critical properties of the one-dimensional quantum Ising model on a programmable superconducting quantum chip via a Kibble-Zurek process, obtain scaling laws, and estimate critical exponents despite inherent sources of errors on the hardware. In addition, we investigate how the improvement of NISQ computers (more qubits, less noise) will consolidate the computation of those universal physical properties. A one-parameter noise model captures the effect of imperfections and reproduces the experimental data. Its systematic study reveals that the noise, analogously to temperature, induces a new length scale in the system. We introduce and successfully verify modified scaling laws, directly accounting for the noise without any prior knowledge. It makes data analyses for extracting physical properties transparent to noise. By understanding how imperfect quantum hardware modifies the genuine properties of quantum states of matter, we enhance the power of NISQ processors considerably for addressing quantum criticality and potentially other phenomena and algorithms.