Quantum state engineering using weak measurement

TL;DR

This paper demonstrates a method for quantum state engineering using weak measurement in a three wave mixing process, enabling high-fidelity preparation of various nonclassical states for quantum information applications.

Contribution

It introduces a novel scheme utilizing postselected weak measurement in three wave mixing to generate specific nonclassical states with high fidelity.

Findings

High-fidelity preparation of single-photon Fock, coherent, and squeezed states.

Analysis of squeezing, amplification, and Wigner functions of output states.

Potential for new nonclassical state generation methods in quantum information.

Abstract

State preparation via postselected weak measurement in three wave mixing process is studied. Assuming the signal input mode prepared in a vacuum state, coherent state or squeezed vacuum state, separately, while the idler input prepared in weak coherent state and passing the medium characterized by the second-order nonlinear susceptibility. It is shown that when the single photon is detected at one of the output channels of idler beam's path, the signal output channel is prepared in single-photon Fock state, single-photon-added coherent state or single-photon-added squeezed vacuum state with very high fidelity, depending upon the input signal states and related controllable parameters. The properties including squeezing, signal amplification, second order correlation and Wigner functions of the weak measurement based output states are also investigated. Our scheme promising to provide alternate new effective method for producing useful nonclassical states in quantum information processing.