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Geometric phase and nonadiabatic effects in an electronic harmonic oscillator
M Pechal1, S Berger, A A Abdumalikov
1Department of Physics, ETH Zurich, CH-8093 Zurich, Switzerland. mpechal@phys.ethz.ch
Physical Review Letters
|June 12, 2012
Summary
Researchers experimentally observed a geometric phase in an electronic harmonic oscillator using a superconducting qubit. The phase is proportional to the enclosed area in the quadrature plane, with negligible dephasing in the non-adiabatic regime.
Area of Science:
- Quantum Optics
- Quantum Information Science
- Condensed Matter Physics
Background:
- Geometric phases in quantum systems are path-dependent phenomena.
- Observing geometric phases in linear systems like harmonic oscillators is challenging due to their inherent linearity.
- Superconducting qubits offer a potential avenue for probing subtle quantum effects.
Purpose of the Study:
- To experimentally observe and characterize the geometric phase in an electronic harmonic oscillator.
- To utilize a superconducting qubit as a nonlinear probe for an otherwise unobservable phase.
- To investigate the behavior of the geometric phase and associated dephasing in the non-adiabatic regime.
Main Methods:
- Implementation of a superconducting qubit coupled to an electronic harmonic oscillator.
- Steering the quantum harmonic oscillator state along various cyclic trajectories.
- Utilizing the qubit's nonlinearity to measure the geometric phase accumulated by the oscillator.
Main Results:
- Experimental observation of a path-dependent geometric phase in the electronic harmonic oscillator.
- Demonstration that the geometric phase is proportional to the enclosed area in the quadrature plane for diverse cyclic paths.
- Identification of parameters that minimize dephasing due to qubit-resonator entanglement, even in the non-adiabatic regime.
Conclusions:
- The study successfully demonstrates the experimental observation of geometric phases in a linear quantum system.
- The developed system serves as a versatile platform for studying geometric phases in open quantum systems.
- The findings highlight the potential of this controllable system for applications in quantum information processing.
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