Quantum Simulation of Generic Many-Body Open System Dynamics Using Classical Noise

Area of Science:

• Quantum Information Science
• Quantum Many-Body Physics
• Quantum Simulation

Background:

• Quantum decoherence is a critical challenge in building scalable quantum computers.
• Simulating open quantum systems accurately is essential for understanding and mitigating decoherence.

Purpose of the Study:

• To introduce a novel scheme for simulating many-body decoherence in quantum systems.
• To demonstrate how stochastic Hamiltonians can model open quantum dynamics.

Main Methods:

• Utilizing the unitary evolution of a stochastic Hamiltonian to simulate decoherence.
• Modulating interaction strengths with stochastic processes (white and colored noise).
• Analyzing the noise-averaged density matrix to reveal effective open dynamics.

Main Results:

• The proposed method simulates open quantum dynamics governed by k-body Lindblad operators.
• Markovian dynamics are achieved with white noise, while colored noise enables non-Markovian dynamics.
• Fidelity decay under many-body decoherence scales as N^{-2k} with system size N.

Conclusions:

• The developed scheme provides a versatile tool for studying many-body decoherence.
• The method is implementable across various quantum platforms like optical lattices, superconducting circuits, and trapped ions.