Variational Quantum Simulation of Lindblad Dynamics via Quantum State Diffusion.

Area of Science:

• Quantum Computing
• Quantum Simulation
• Open Quantum Systems

Background:

• Simulating dynamics in open quantum systems is essential but challenging due to non-unitary evolution and limited quantum resources.
• The Lindblad master equation describes the time evolution of open quantum systems, often requiring significant computational power.

Purpose of the Study:

• To introduce a novel variational hybrid quantum-classical algorithm for simulating open quantum system dynamics.
• To reduce qubit requirements for simulating non-unitary evolution using a wave function-based approach.

Main Methods:

• Developed a hybrid algorithm combining Quantum State Diffusion (QSD) with Variational Quantum Simulation (VQS).
• Transformed the Lindblad master equation into a QSD method to decrease qubit usage.
• Applied VQS to efficiently capture the non-unitary dynamics within the QSD framework.

Main Results:

• Successfully demonstrated the QSD-VQS algorithm on a two-level system with amplitude damping.
• Investigated quantum dynamics in a four-level transverse field Ising model under a dissipative environment.
• Showcased the algorithm's capability in handling both time-independent and periodic Hamiltonians.

Conclusions:

• The QSD-VQS algorithm offers a promising approach for simulating open quantum systems on near-term quantum hardware.
• The method effectively addresses challenges posed by non-unitary evolution and resource limitations in quantum simulations.