Publications by authors named "Lupei Qin"
Article Synopsis
- - The weak-value-amplification (WVA) scheme in precision metrology utilizes quantum destructive interference from pre- and post-selection states, while the joint WVA (JWVA) method offers even greater sensitivity, despite some technical challenges like misalignment errors.
- - This work explores the difference-signal amplification (DSA) technique as a classical alternative to JWVA, demonstrating that comparable amplification effects can be achieved after erasing quantum coherence.
- - A simplified expression for the amplified signal is developed along with a precision characterization, and the research discusses implementing post-selection in classical mixed states, suggesting practical applications for the DSA technique.
Article Synopsis
- The proposed scheme focuses on measuring the quantum state of photons in a cavity using quantum weak values, applicable to both solid-state circuits and atomic cavity QED systems.
- This approach allows for direct access to superposition components in the Fock state basis, rather than relying on the traditional Wigner function in phase space.
- Unlike conventional quantum state tomography, the method enables separate access to quantum states without needing global reconstruction, offering a significant advantage.
Developing efficient framework for quantum measurements is of essential importance to quantum science and technology. In this work, for the important superconducting circuit-QED setup, we present a rigorous and analytic solution for the effective quantum trajectory equation (QTE) after polaron transformation and converted to the form of Stratonovich calculus. We find that the solution is a generalization of the elegant quantum Bayesian approach developed in arXiv:1111.
View Article and Find Full Text PDFIn this work we revisit the important and controversial concept of quantum weak values, aiming to provide a simplified understanding to its associated physics and the origin of anomaly. Taking the Stern-Gerlach setup as a working system, we base our analysis on an exact treatment in terms of quantum Bayesian approach. We also make particular connection with a very recent work, where the anomaly of the weak values was claimed from the pure statistics in association with "disturbance" and "post-selection", rather than the unique quantum nature.
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