The dynamical Casimir effect in a superconducting coplanar waveguide

TL;DR

This paper demonstrates how modulating a superconducting waveguide boundary with a SQUID can generate broadband photons via the dynamical Casimir effect, offering a feasible way for experimental detection of nonclassical radiation.

Contribution

It introduces a method to realize the dynamical Casimir effect in a superconducting waveguide using a SQUID to modulate boundary conditions.

Findings

Broadband photon generation observed with effective boundary velocities near the speed of light.

Estimated radiation power suggests experimental feasibility for detection.

Photon spectra consistent with theoretical predictions of the dynamical Casimir effect.

Abstract

We investigate the dynamical Casimir effect in a coplanar waveguide (CPW) terminated by a superconducting quantum interference device (SQUID). Changing the magnetic flux through the SQUID parametrically modulates the boundary condition of the CPW, and thereby, its effective length. Effective boundary velocities comparable to the speed of light in the CPW result in broadband photon generation which is identical to the one calculated in the dynamical Casimir effect for a single oscillating mirror. We estimate the power of the radiation for realistic parameters and show that it is experimentally feasible to directly detect this nonclassical broadband radiation.