Nonlinear nonequilibrium quasiparticle relaxation in Josephson junctions

Abstract

Nonequilibrium electrons in superconductors relax and eventually recombine into Cooper pairs. Relaxation is facilitated by electron-boson interaction and is accompanied by emission of nonequilibrium bosons. Here I solve numerically a full set of nonlinear kinetic balance equations for stacked Josephson junctions, which allows analysis of strongly nonequilibrium phenomena. It is shown that nonlinearity becomes significant already at very small disequilibrium. The following new, essentially nonlinear effects are obtained: (i) At even-gap voltages $V=2n\Delta /e$ $(n=2,3,...)$ nonequilibrium bosonic bands overlap. This leads to enhanced emission of $\Omega =2\Delta$ bosons and to appearance of dips in tunnel conductance. (ii) A new type of radiative solution is found at strong disequilibrium. It is characterized by the fast stimulated relaxation of nonequilibrium quasiparticles. A stack in this state behaves as a light emitting diode and directly converts electric power to boson emission, without utilization of the ac-Josephson effect. This leads to very high radiation efficacy and to significant radiative cooling of the stack. The phenomenon can be used for realization of a new type of superconducting cascade laser in the THz frequency range.

4 pages, 4 figures and a supplementary

References in corpus (4)

• Hot spots and waves in Bi2Sr2CaCu2O8 intrinsic Josephson junction stacks -a study by Low Temperature Scanning Laser Microscopy
• Quasiparticle relaxation in optically excited high-Q superconducting resonators
• Temperature dependence of the bulk energy gap in underdoped Bi-2212: Evidence for the mean-field superconducting transition
• Quantum cascade phenomenon in natural atomic superlattices formed in Bi2Sr2CaCu2O8 single crystals

Cited by in corpus (20)

• Coherent THz emission of Bi_2Sr_2CaCu_2O_8 intrinsic Josephson junction stacks in the hot spot regime
• Interaction of hot spots and THz waves in Bi_2Sr_2CaCu_2O_8 intrinsic Josephson junction stacks of various geometry
• Unusual linewidth dependence of coherent THz emission measured from intrinsic Josephson junction stacks in the hot-spot regime
• Phase dynamics of inductively coupled intrinsic Josephson junctions and terahertz electromagnetic radiation
• Hot-spot formation in stacks of intrinsic Josephson junctions in Bi2Sr2CaCu2O8
• THz emission from intrinsic Josephson junctions at zero magnetic field via breather auto-oscillations
• THz emission from a stacked coherent flux-flow oscillator: non-local radiative boundary conditions and the role of geometrical resonances
• Thermal and electromagnetic properties of Bi${}_2$Sr${}_2$CaCu${}_2$O${}_8$ intrinsic Josephson junction stacks studied via one-dimensional coupled sine-Gordon equations
• Observation of superluminal geometrical resonances in Bi2Sr2CaCu2O8+x intrinsic Josephson junctions
• 3D simulations of the electrothermal and THz emission properties of Bi${}_2$Sr${}_2$CaCu${}_2$O${}_8$ intrinsic Josephson junction stacks
• High bias anomaly in YBa2Cu3O7/LaMnO_{3+delta}/YBa2Cu3O7 Superconductor/Ferromagnetic Insulator/Superconductor junctions: Evidence for a long-range superconducting proximity effect through the conduction band of a ferromagnetic insulator
• Observation of polaritons in Bi2Sr2CaCu2O8+x single crystals
• Temperature dependence of geometrical and velocity matching resonances in Bi2Sr2CaCu2O8+x intrinsic Josephson junctions
• Comparative analysis of tunneling magnetoresistance in low-$T_c$ Nb/AlAlOx/Nb and high-$T_c$ Bi${}_{2-y}$Pb${}_y$Sr${}_2$CaCu${}_2$O${}_{8+\delta }$ intrinsic Josephson junctions
• Persistent electrical doping of Bi2Sr2CaCu2O8+x mesa structures
• Variation of Longitudinal Plasma Wavelength under Irradiation and Double Resonance in Coupled Josephson Junctions
• Comment on Counterintuitive consequence of heating in strongly driven intrinsic junctions of Bi${}_2$Sr${}_2$CaCu${}_2$O${}_{8+\delta }$ mesas
• Strong polaritonic interaction between flux-flow and phonon resonances in Bi2Sr2CaCu2O8+x intrinsic Josephson junctions: Angular dependence and the alignment procedure
• Quantization of the superconducting energy gap in an intense microwave field
• Shapiro Step at Nonequilibrium Conditions