One-photon Solutions to Multiqubit Multimode quantum Rabi model

TL;DR

This paper presents special solutions to the multiqubit multimode quantum Rabi model with at most one photon, enabling fast generation of multimode W states and proposing a superconducting circuit implementation.

Contribution

It introduces a novel class of solutions with at most one photon for arbitrary qubit and mode numbers, and proposes practical schemes and circuit designs for realization.

Findings

Existence of special solutions with at most one photon for any number of qubits and modes.

An adiabatic scheme for fast generation of multimode W states with less than 1% nonadiabatic error.

A superconducting circuit design demonstrating experimental feasibility.

Abstract

General solutions to the quantum Rabi model involve subspaces with unbounded number of photons. However, for the multiqubit multimode case, we find special solutions with at most one photon for arbitrary number of qubits and photon modes. Unlike the Juddian solution, ours exists for arbitrary single qubit-photon coupling strength with constant eigenenergy. This corresponds to a horizontal line in the spectrum, while still being a qubit-photon entangled state. As a possible application, we propose an adiabatic scheme for the fast generation of arbitrary single-photon multimode W states with nonadiabatic error less than 1%. Finally, we propose a superconducting circuit design, showing the experimental feasibility of the multimode multiqubit Rabi model.