# Behavior of two-level quantum system driven by non-classical inputs

## TL;DR

This paper investigates how a two-level quantum system behaves when driven by non-classical light states, revealing that stochastic master equations provide more detailed system information than traditional master equations.

## Contribution

It introduces an analysis of a two-level quantum system driven by various non-classical states using quantum filtering, highlighting the advantages of stochastic master equations over standard approaches.

## Key findings

- Stochastic master equations contain more information about the system state.
- Purity of the system state varies with different input states.
- Behavior differs significantly when driven by vacuum, single photon, or superposition states.

## Abstract

Two level quantum system (Qubit) and non-classical states of light such as single photon and superposition of coherent state are under special attention in quantum technologies such as quantum computing, quantum communication and quantum computers. So, behavior of two-level system driven by such inputs is important. In this paper, the behavior of two-level quantum system driven by vacuum state, single photon and superposition of coherent state was investigated by assuming Pauli matrices as system operators in quantum filtering equations. The purity of conditioned and unconditioned state are also analyzed when the system is driven by different inputs. The results show that the stochastic master equation dynamic has more information about the status of system than master equation dynamic.