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Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
Published on: August 2, 2019
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Observing single quantum trajectories of a superconducting quantum bit.
K W Murch1, S J Weber, C Macklin
1Quantum Nanoelectronics Laboratory, Department of Physics, University of California, Berkeley, California 94720, USA. steppenbeck@cns.s.u-tokyo.ac.jp
Nature
|October 11, 2013
Summary
Environmental monitoring can mitigate quantum decoherence by tracking quantum trajectories. This study demonstrates real-time measurement of a superconducting qubit
Area of Science:
- Quantum Physics
- Quantum Information Science
- Superconducting Circuits
Background:
- Quantum systems lose their superposition states due to environmental interactions, a process called decoherence.
- Decoherence transforms pure quantum states into statistical mixtures, limiting quantum computation and information processing.
- Real-time environmental measurement offers a potential pathway to maintain quantum purity and control system evolution.
Purpose of the Study:
- To experimentally demonstrate the mitigation of decoherence through environmental monitoring.
- To track individual quantum trajectories of a superconducting qubit in real time.
- To validate quantum feedback theories and explore new quantum control mechanisms.
Main Methods:
- Utilizing weak measurements to monitor a superconducting qubit within a microwave cavity.
- Employing a near-quantum-limited parametric amplifier to selectively measure cavity field phase or amplitude.
- Performing quantum state tomography to verify the tracked quantum trajectories on the Bloch sphere.
Main Results:
- Successfully tracked individual quantum trajectories of the superconducting qubit.
- Demonstrated that environmental monitoring effectively mitigates decoherence.
- Verified the confinement of quantum trajectories to specific paths on the Bloch sphere.
Conclusions:
- Environmental monitoring is a viable strategy to combat decoherence in quantum systems.
- The experimental results validate Bayesian statistics for quantum feedback control.
- The study opens avenues for implementing quantum steering for remote quantum state manipulation.
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