Microwave-Assisted Unidirectional Superconductivity in Al-InAs Nanowire-Al Junctions under Magnetic Fields.

Area of Science:

• Condensed Matter Physics
• Quantum Materials

Background:

• The superconducting diode effect describes asymmetric critical currents in superconductors under specific conditions.
• Unidirectional superconductivity, a key aspect of the diode effect, is crucial for advanced superconducting electronics.

Purpose of the Study:

• To investigate the superconducting diode effect in Al-InAs nanowire-Al Josephson junctions.
• To explore the influence of microwave irradiation and magnetic fields on unidirectional superconductivity.

Main Methods:

• Fabrication of Al-InAs nanowire-Al Josephson junctions.
• Experimental measurements of voltage-current characteristics under varying microwave power and magnetic fields.

Main Results:

• Observed enhancement of the superconducting diode effect with increasing microwave power.
• Achieved unidirectional superconductivity at high microwave driving amplitudes.
• Demonstrated magnetic field direction reversal alters the offset sign.
• Noted a near-linear response of the offset magnitude to microwave power (in dBm) under strong fields.

Conclusions:

• Microwave irradiation significantly enhances the superconducting diode effect in these junctions.
• The observed phenomena align with theoretical predictions but deviate in some aspects, suggesting novel mechanisms.
• Potential for new physics related to nonequilibrium dynamics or dissipation in driven superconducting systems.