Dynamically enhancing qubit-photon interactions with anti-squeezing

TL;DR

This paper demonstrates that squeezing an oscillator in a superconducting circuit can dynamically enhance qubit-photon interactions, achieving a two-fold increase in dispersive coupling, thus opening new avenues for quantum control.

Contribution

It provides the first experimental demonstration of dynamically boosting qubit-photon interactions using oscillator squeezing in superconducting circuits.

Findings

Two-fold increase in dispersive interaction at 5.5 dB squeezing

In-situ dynamical control of qubit-photon coupling achieved

Experimental coupling of squeezed photon oscillators to qubits demonstrated

Abstract

The interaction strength of an oscillator to a qubit grows with the oscillator's vacuum field fluctuations. The well known degenerate parametric oscillator has revived interest in the regime of strongly detuned squeezing, where its eigenstates are squeezed Fock states. Owing to these amplified field fluctuations, it was recently proposed that squeezing this oscillator would dynamically boost qubit-photon interactions. In a superconducting circuit experiment, we observe a two-fold increase in the dispersive interaction between a qubit and an oscillator at 5.5 dB of squeezing, demonstrating in-situ dynamical control of qubit-photon interactions. This work initiates the experimental coupling of oscillators of squeezed photons to qubits, and cautiously motivates their dissemination in experimental platforms seeking enhanced interactions.