Periodic Phase Slips and Frequency Comb Generation at Tunable Microwave Frequencies in Superconducting Diabolo...

Area of Science:

• Condensed Matter Physics
• Quantum Technologies
• Nanotechnology

Background:

• Superconductors exhibit macroscopic phase coherence, crucial for cryogenic electronics and quantum technologies.
• Advances in 3D nanofabrication enable on-chip integration of superconductors.
• Nonequilibrium phenomena in 3D superconducting nanostructures under transport currents are underexplored.

Purpose of the Study:

• To numerically investigate phase slips in a 3D tubular niobium (Nb) superconductor with a central constriction.
• To analyze the effects of direct current (DC) and alternating current (AC) transport currents on phase slip dynamics.

Main Methods:

• Numerical simulations were employed to model the behavior of a superconducting nanostructure.
• The study focused on phase slips, which are discrete 2π jumps in the superconducting order parameter.
• Both DC and AC transport currents were applied to the simulated system.

Main Results:

• Under DC drive, the system exhibited periodic phase slips, leading to GHz voltage oscillations.
• Introducing AC frequency modulation generated microwave frequency combs.
• The generated frequency combs showed characteristic dependence on the interaction between moving vortices and phase slips.

Conclusions:

• The study reveals novel nonequilibrium phenomena in 3D superconducting nanostructures.
• The findings demonstrate the potential for developing on-chip frequency comb generators.
• This research opens new avenues for 3D cryoelectronics and quantum device applications.