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Aharonov-Bohm oscillations with spin: evidence for Berry's phase
Jeng-Bang Yau1, E P De Poortere, M Shayegan
1Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA.
Physical Review Letters
|April 17, 2002
Summary
We studied the Aharonov-Bohm effect in a GaAs system. The geometric phase acquired by carrier spin explains extra oscillations observed in resistance, revealing insights into quantum phenomena.
Area of Science:
- Condensed matter physics
- Quantum mechanics
- Mesoscopic systems
Background:
- The Aharonov-Bohm effect describes flux-dependent resistance oscillations in mesoscopic rings.
- Strong spin-orbit interaction in semiconductor systems can influence quantum phenomena.
Purpose of the Study:
- To investigate the Aharonov-Bohm effect in a GaAs two-dimensional hole system.
- To understand the origin of extra structure observed in the Fourier spectra of resistance oscillations.
Main Methods:
- Experimental measurement of resistance oscillations in a mesoscopic ring subjected to a perpendicular magnetic field.
- Analysis of Fourier spectra of the oscillations.
- Comparison with simulation results.
Main Results:
- Observed oscillations in resistance as a function of magnetic field, characteristic of the Aharonov-Bohm effect.
- Identified extra structure in the Fourier spectra near the main peak.
- Correlated the frequency of this extra structure with the magnetic flux enclosed by the ring.
Conclusions:
- The extra structure in the Fourier spectra is attributed to the geometric (Berry) phase acquired by the carrier spin.
- This finding highlights the role of spin-orbit interaction and geometric phase in mesoscopic quantum transport.