Simulating long-range hopping with periodically-driven superconducting qubits

TL;DR

This paper demonstrates how to simulate long-range hopping in quantum lattice models using periodically-driven superconducting qubits, enabling tunable decay exponents and exploring nonequilibrium phenomena.

Contribution

It introduces a method to simulate long-range interactions via engineered periodic drives in superconducting qubits, with experimental protocols to analyze eigenfunction scaling.

Findings

Successful simulation of tunable long-range hopping with power-law decay.

Experimental protocols to probe Floquet eigenfunction tails.

Identification of a scaling transition between weak and strong long-range couplings.

Abstract

Quantum computers are a leading platform for the simulation of many-body physics. This task has been recently facilitated by the possibility to program directly the time-dependent pulses sent to the computer. Here, we use this feature to simulate quantum lattice models with long-range hopping. Our approach is based on an exact mapping between periodically driven quantum systems and one-dimensional lattices in the synthetic Floquet direction. By engineering a periodic drive with a power-law spectrum, we simulate a lattice with long-range hopping, whose decay exponent is freely tunable. We propose and realize experimentally two protocols to probe the long tails of the Floquet eigenfunctions and to identify a scaling transition between weak and strong long-range couplings. Our work offers a useful benchmark of pulse engineering and opens the route towards quantum simulations of rich nonequilibrium effects.