Toward the Light‐Operated Superconducting Devices: Circularly Polarized Radiation Manipulates the Current‐Carrying States in Superconducting Rings

Abstract

The ability to rapidly control and manipulate superconducting states is one of the great challenges of modern condensed matter physics. Circularly polarized radiation interacting with a superconducting condensate acts as an effective magnetic field that can generate supercurrents and DC magnetic moments through the inverse Faraday effect (IFE). Using the time-dependent Ginzburg-Landau (TDGL) equation formalism, the current-carrying states of a small superconducting ring illuminated by such radiation is calculated. Numerical simulations demonstrate the possibility to on-demand switch between current-carrying states in the superconductor by controlling the helicity of the electromagnetic field polarization. This result opens the way to all-optical operation of superconducting devices.

Dynamics of Dispersive Measurements of Flux-Qubit States: Energy-Level Splitting Connected to Quantum Wave Mechanics

“…The information developed here can be usefully applied in designing both a flux qubit and a readout system of qubit signals. Though we adopted the flux qubit coupled to the SQUID, our development can be tailored for the purpose of describing other similar systems and structures, such as readout mechanisms for other types of qubits and the interaction of radiation with superconducting rings [18,[42][43][44].…”

Locating Two-Level Systems in a Superconducting Xmon Qubit

“…The analytical methods used in this paper are effective tools to analyze the longterm stability of the quantum system parameters, such as decoherence times of quantum dots [46], optical gains of laser diodes using quantum wires [47,48], and spontaneous currents in superconducting rings [49,50], and are not limited to the superconducting qubit system discussed here. The presence of fluctuations in T 1 , T R 2 and qubit frequency highlights the importance of recalibrating qubits frequently, as these fluctuations contribute to errors in quantum gate fidelities and quantum teleportation fidelities [51,52], and this study provides an approach for selecting the ideal working points of tunable superconducting Xmon qubits to avoid the unstable area.…”

All-optical generation of Abrikosov vortices by the Inverse Faraday Effect

“…In the case of a superconducting system, the light-induced dynamics of the order parameter comprises a nondissipative oscillatory contribution, which arises from the imaginary part of the order parameter relaxation time and creates the currents maintaining a nonzero magnetic moment [28]. It was theoretically shown [29,30] that the interplay of the Kibble-Zurek mechanism and IFE in the case of a superconducting ring leads to the generation of the circulating current states with the rotation directions controlled by the external light polarization.…”