Controlled terahertz frequency response and transparency of Josephson chains and superconducting multilayers

Abstract

A fundamental property of wave propagation is Anderson localization, which affects the transfer of information, energy, mass, and charge in disordered media. This localization can manifest itself via, e.g., the metal-insulator transition. We exactly map the behavior of a quantum particle moving in a potential with correlated disorder to the sub-terahertz wave propagation in either Josephson chains or superconducting multilayers. When the Josephson junction parameters vary randomly, the sub-THz electromagnetic waves cannot propagate through these Josephson structures due to localization. For parameter variations with long-range correlations, we predict sharp transitions from transparent to reflective frequency regions for Josephson plasma waves. With appropriate choices of the correlation function, frequency windows with targeted or designed transparencies for THz or sub-THz electromagnetic waves could be achieved. This could be useful for tailoring the electromagnetic wave spectrum of Josephson arrays within the THz frequency range, which is important for applications in physics, astronomy, chemistry, biology, and medicine.

Conducting to non-conducting transition in dual transmission lines using a ternary model with long-range correlated disorder

“…Experimental evidence of delocalization produced by correlated disorder has been shown in the study of microwave propagation through disordered waveguides [18] and subterahertz response of superconducting multilayer [19] and in semiconductor superlattices with intentional disorder [20].…”

How the site degree influences quantum probability on inhomogeneous substrates

“…This knowledge may have practical importance, for instance, in the field of quantum information, where we know that information is generated, processed and stored locally on quantum nodes [31], or in Josephson photonic structures, where it is possible to make an analogy between the behavior of quantum particles and wave propagation, in which the frequency response can be controlled by tuning a magnetic field [32].…”

Quantum metamaterial without local control

“…Figures 2 and 3 show the results of a numerical simulation of such a process from Eqs. (7) and (9). Two priming pulses at t = 0 are located in the passive regions of the waveguide (Fig.…”

“…6,7 The emission of terahertz radiation due to the ac Josephson effect allows to build Josephson-based emitters, filters, detectors, and waveguides operating in this spectral range that is important for applications. 8,9 The nonlinear effective inductance of Josephson junctions makes them a convenient basis for nonlinear metamaterials. 10 Another fundamentally novel class of artificial media are quantum metamaterials, i.e., optical media, which maintain global quantum coherence over times exceeding the signal transition time and allow local control over quantum states and basic properties of their constituent elements.…”