Abstract
The preparation of thermal states is an important task in quantum computation with applications in quantum simulation, quantum optimization, and quantum machine learning. In this proposal, I review several algorithms on thermal state preparation. Then I focus on an algorithm for thermofield double state preparation by imaginary time evolution, which is implemented by powered Hamiltonian approximation and linear combination of unitaries. I demonstrate this algorithm by simulating quantum Ising model. I propose to: 1) apply the algorithm on other models e.g. XY model, Heisenberg model, Hubbard model, etc.; 2) optimize the algorithm by analysing circuit complexity, query complexity and quantum resource consumption; 3) design a full qubit circuit or hybrid quantum-classical circuit based on the algorithm and discuss its physical implementation. Our quantum algorithm provides a promising method for quantum thermal simulation.
Anyone interested is welcome to attend.