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Updated: Jun 12, 2026
12:57
Resonance Fluorescence of an InGaAs Quantum Dot in a Planar Cavity Using Orthogonal Excitation and Detection
Published on: October 13, 2017
Fast spin rotations by optically controlled geometric phases in a charge-tunable InAs quantum dot
Erik D Kim1, Katherine Truex, Xiaodong Xu
1The H. M. Randall Laboratory of Physics, The University of Michigan, Ann Arbor, Michigan 48109, USA.
Physical Review Letters
|May 21, 2010
Summary
Researchers optically controlled electron spin phase in quantum dots using cyclic excitations. This geometric phase acts as a spin phase gate, crucial for advancing quantum information applications.
Area of Science:
- Quantum physics
- Condensed matter physics
- Optoelectronics
Background:
- Electron spins in quantum dots are fundamental for quantum computing.
- Controlling spin states with optical methods is challenging but essential.
- Geometric phase offers a robust way to encode quantum information.
Purpose of the Study:
- To demonstrate optical control over the geometric phase of an electron spin in an Indium Arsenide (InAs) quantum dot.
- To explore the potential of optically induced geometric phases as a spin phase gate for quantum information processing.
Main Methods:
- Utilizing cyclic 2pi excitations of an optical transition in a charge-tunable InAs quantum dot.
- Applying a constant in-plane magnetic field to influence spin dynamics.
- Analyzing spin quantum beat signals generated by time-delayed, circularly polarized optical pulses.
Main Results:
- Successfully demonstrated optical control of geometric phase for an electron spin state.
- Observed that optically induced geometric phases cause effective spin rotation around the magnetic field axis.
- Phase shifts in spin quantum beat signals confirmed the geometric phase acquisition.
Conclusions:
- Optically controlled geometric phases can serve as a spin phase gate.
- This technique shows promise for developing new quantum information applications.
- The study highlights the potential of InAs quantum dots for quantum control.
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