Equilibrium circular photogalvanic effect in a hybrid superconductor-semiconductor system

Area of Science:

• Condensed Matter Physics
• Quantum Optics
• Materials Science

Background:

• Hybrid systems integrating semiconductors and superconductors offer unique electronic and optical properties.
• Understanding light-matter interactions in these systems is crucial for developing novel quantum technologies.
• The Meissner effect describes the expulsion of magnetic fields from superconductors, a phenomenon typically observed in static magnetic fields.

Purpose of the Study:

• To investigate the induction of direct current (dc) in hybrid semiconductor-superconductor systems.
• To explore the influence of circularly polarized light on these systems below the semiconductor's interband transition energy.
• To establish a connection between this light-induced effect and the Meissner effect.

Main Methods:

• Illumination of a hybrid semiconductor-superconductor system with circularly polarized light.
• Operating at frequencies below the semiconductor's interband transition energy to prevent real electron-hole excitations.
• Observing and analyzing the induced dc electric current.

Main Results:

• A dc electric current was successfully induced in the hybrid system under specific illumination conditions.
• The induced current was observed even when the light did not generate real electron-hole excitations.
• The phenomenon exhibited characteristics analogous to the Meissner effect in the presence of a static magnetic field.

Conclusions:

• Hybrid semiconductor-superconductor systems can exhibit light-induced dc currents without generating electron-hole excitations.
• This effect provides a novel way to manipulate superconducting states using light, reminiscent of the Meissner effect.
• The findings suggest potential applications in integrating cavity photons with superconducting quantum circuits.