Study of decoherence of a superposition of macroscopic quantum states by means the consideration of a multimode state of a Schrodinger cat

TL;DR

This paper introduces a method to estimate the coherence of high-dimensional Schrödinger cat states by analyzing multimode quantum states, providing formulas for reduced states and implications for quantum information processing.

Contribution

It presents a new approach to quantify coherence in multimode Schrödinger cat states and simplifies their analysis by reducing them to two-mode analogs.

Findings

Derived a quantitative relationship between coherence and Schmidt number.

Developed formulas for reduced states after mode measurements.

Applicable to high-dimensional quantum information systems.

Abstract

Quantum Schrodinger cat states are of great interest in quantum communications and quantum optics. These states are used in various scientific fields such as quantum computing, quantum error correction and high-precision measurements. The analysis of the Schrodinger cat states coherence is an important task for their complete practical application. Our developed approach makes it possible to estimate the coherence of the quantum Schrodinger cat state of arbitrary dimension, as well as to find the interference visibility of the state - an important optical characteristic. The obtained simple quantitative relationship between coherence and the Schmidt number, as well as the developed approach of reducing the multidimensional quantum cat state to a two-mode analog allow us to analyze macroscopic states formed by a large number of modes. Several explicit formulas for the reduced states that arise after measuring of some modes of the considered multimode system are obtained. The research results have significant application and can be used in the development of high-dimensional quantum information processing systems.