Detection of persistent current correlation in cavity-QED

Abstract

We simulated the radiative response of the cavity quantum electrodynamics (QED) inductively coupled to the ring pierced by magnetic flux, and analyzed its spectral dependence to get insight into persistent current dynamics. Current fluctuations in the ring induce changes in the microwave resonator: shifting the resonant frequency and changing its damping. We use the linear response theory and calculate the current response function by means of the Green function technique. Our model contains two quantum dots which divide the ring into two arms with different electron transfers. There are two opposite (symmetric and asymmetric) components of the persistent current, which interplay can be observed in the response functions. The resonator reflectance shows characteristic shifts in the dispersive regime and avoided crossings at the resonance points. The magnitude of the resonator frequency shift is greater for coupling to the arm with higher transparency. Fluctuations of the symmetric component of the persistent current are relevant for a wide range of the Aharovov-Bohm phase $\varphi$, while the asymmetric component becomes dominant close to $\varphi \approx \pi$ (when the total persistent current changes its orientation)

arXiv comment5 pages, 4 figures, presented at European Conf. PHYSICS OF MAGNETISM 2023 (PM'23), June 26-30, Poznan, Poland

References in corpus (18)

• Shot Noise in Mesoscopic Conductors
• Circuit Quantum Electrodynamics
• Ultrastrong coupling regimes of light-matter interaction
• Josephson and Andreev transport through quantum dots
• Coherent manipulation of Andreev states in superconducting atomic contacts
• Superconductor-semiconductor hybrid cavity quantum electrodynamics
• Zero-Point Fluctuations and the Quenching of the Persistent Current in Normal Metal Rings
• Microwave Emission from Hybridized States in a Semiconductor Charge Qubit
• Circuit-QED with phase-biased Josephson weak links
• Quantum behaviour of a flux qubit coupled to a resonator
• Zero-point fluctuations in the ground state of a mesoscopic normal ring
• Josephson effect in topological superconducting rings coupled to a microwave cavity
• Realization of a $C{Q}_3$ Qubit: energy spectroscopy and coherence
• Theory of interactions between cavity photons induced by a mesoscopic circuit
• Inductive microwave response of Yu-Shiba-Rusinov states
• Persistent current noise and electron-electron interactions
• Persistent currents in ballistic normal-metal rings
• Full counting statistics of persistent current