Enhancement of persistent currents and magnetic fields in a two dimensional quantum ring.

Area of Science:

• Quantum physics
• Condensed matter physics
• Nanotechnology

Background:

• Quantum rings (QRs) exhibit unique electronic properties.
• Silicon-germanium (SiGe) alloys are promising for quantum devices.
• Controlling quantum phenomena with external fields is crucial for device applications.

Purpose of the Study:

• To investigate the control of induced current and magnetic field in SiGe QRs using femtosecond laser pulses (FLPs).
• To analyze the influence of spin-orbit interaction (SOI) and Zeeman energy on these induced fields.
• To explore the interplay between confinement strength, FLPs, and SOI.

Main Methods:

• Modeling SiGe QRs using an anharmonic axially symmetric potential with a centrifugal core.
• Applying the effective mass approximation for calculations.
• Simulating the effects of femtosecond laser pulses (FLPs) on the quantum system.
• Analyzing the impact of spin-orbit interaction (SOI) and Zeeman energy.

Main Results:

• FLPs significantly alter induced currents and magnetic fields in SiGe QRs.
• Spin-orbit interaction (SOI) and Zeeman energy play a substantial role in generating and enhancing these fields.
• The presence of SOI, when competing with confinement, reduces the strength of induced currents and fields under FLP influence.

Conclusions:

• Femtosecond laser pulses offer an effective method for controlling quantum phenomena in SiGe nanostructures.
• Spin-orbit interaction is a critical factor influencing magnetic and current generation in these systems.
• Understanding these interactions is key for developing novel spintronic and quantum devices.