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09:23
Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators
Published on: May 30, 2014
Coherent quasiclassical dynamics of a persistent current qubit.
D M Berns1, W D Oliver, S O Valenzuela
1Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Physical Review Letters
|December 13, 2006
Summary
Researchers observed a new quantum dynamics regime in qubits at low driving frequencies. Quantum interference effects, driven by the Landau-Zener process, create observable oscillations in qubit populations, even in the presence of decoherence.
Area of Science:
- Quantum physics
- Quantum computing
- Solid-state physics
Background:
- Understanding coherent quantum dynamics is crucial for developing quantum technologies.
- The Landau-Zener process describes transitions at avoided energy level crossings.
- Previous studies focused on high driving frequencies for observing multiphoton resonances.
Purpose of the Study:
- To investigate a new regime of coherent quantum dynamics in qubits at low driving frequencies.
- To explore quantum interference effects under strong driving conditions.
- To analyze the persistence of interference phenomena below the decoherence rate.
Main Methods:
- Experimental realization of coherent quantum dynamics in a qubit system.
- Utilizing the Landau-Zener process for qubit state transitions.
- Sweeping the system through an energy-level avoided crossing.
- Theoretical modeling incorporating dephasing effects.
Main Results:
- A new regime of coherent qubit dynamics was achieved at low driving frequencies.
- Quantum interference, mediated by repeated Landau-Zener transitions, caused oscillatory qubit populations.
- Interference fringes persisted even when driving frequencies were below the decoherence rate, obscuring individual multiphoton resonances.
Conclusions:
- The study demonstrates a novel regime of quantum dynamics in qubits.
- Quantum interference plays a significant role in qubit behavior at low frequencies and strong driving.
- The theoretical model accurately predicts observed phenomena, including the impact of dephasing.
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