Nuclear-spin-induced oscillatory current in spin-blockaded quantum dots.

Area of Science:

• Quantum physics
• Condensed matter physics
• Materials science

Background:

• Electron transport in semiconductor nanostructures is crucial for quantum technologies.
• Nuclear spin interactions can influence electron spin dynamics in quantum dots.
• Understanding these interactions is key to controlling quantum systems.

Purpose of the Study:

• To experimentally investigate the influence of nuclear spin states on electron transport in GaAs-based double quantum dots.
• To explore the regime where electron spin flip is absent and transport is blocked.
• To analyze the oscillatory behavior of current and its dependence on magnetic fields.

Main Methods:

• Experimental measurements of electron transport through GaAs double quantum dots.
• Application of varying magnetic fields to observe transport characteristics.
• Use of continuous wave ac magnetic fields to induce nuclear magnetic resonance (NMR) in Gallium-69 and Gallium-71 isotopes.

Main Results:

• Electron transport is shown to be affected by ambient nuclear spin states in a specific regime.
• Current oscillations with periods up to 200 seconds were observed, dependent on the magnetic field.
• The observed oscillations were quenched by applying an ac magnetic field, indicating nuclear magnetic resonance.

Conclusions:

• Ambient nuclear spins significantly impact electron transport in GaAs double quantum dots.
• Nuclear spin polarization dynamics can be influenced by electron spin interactions.
• The findings suggest a mechanism for dynamically polarizing nuclear spins, relevant for quantum information processing.