Variational Quantum Algorithms for State Preparation and Dynamics Simulations of Many-Body Models

by Peter Orth (Universiät des Saarlandes)

Tuesday 18 Jun 2024, 13:00 → 14:00 Europe/Berlin

SR 4

We discuss variational quantum algorithms for the simulation of many-body models at zero and finite temperature. At zero temperature, we discuss a hybrid quantum-classical Krylov subspace expansion method that allows to balance the required quantum and classical resource costs. At finite temperature, we discuss algorithms that combine classical sampling techniques with state preparation on quantum hardware. These algorithms work with shallow quantum circuits at an increased classical sampling cost. We discuss how the execution of these algorithms on noisy simulators and hardware benefits from quantum error mitigation methods such as probabilistic error reduction and postselection. Finally, we present hybrid quantum-classical algorithms for the simulation of quantum quench dynamics, starting from the ground or a thermal state. We describe how classical sampling can avoid thermal state preparation on quantum hardware and estimate the associated costs. We show applications of these algorithms to mixed field Ising models.

 

[1] J. C. Getelina et al., Quantum subspace expansion in the presence of hardware noise, arXiv:2404.09132 (2024).

[2] J. C. Getelina et al., Adaptive variational quantum minimally entangled typical thermal states for finite temperature simulations, SciPost Phys. 15, 102 (2023).

[3] I-Chi Chen et al., Problem-tailored Simulation of Energy Transport on Noisy Quantum Computers, arXiv:2310.03924 (2023).

[4] J. Saroni et al., Reconstructing Thermal Quantum Quench Dynamics from Pure States, Phys. Rev. B 108, 134301 (2023).

 

Short Bio: Peter P. Orth is a theoretical condensed matter physicist who works on understanding and predicting properties of quantum materials. He explores quantum materials in and away from equilibrium using analytical field theory and quantum computing algorithms. Peter P. Orth is currently Professor in the Department of Physics at Saarland University, Germany. He also holds an Affiliate Associate Professor position in the Department of Physics and Astronomy at Iowa State University and is a Contributing Scientist at Ames National Laboratory. He is a co-leader in the quantum algorithm thrust of the U.S. Department of Energy National Quantum Initiative Center on "Superconducting Quantum Materials and Systems" (SQMS), where he develops and implements quantum computing algorithms to simulate many-body systems on noisy hardware. He received a Diploma in Physics at the Universität Heidelberg in 2007, and a Ph.D. at Yale University in 2011 under the supervision of Prof. Karyn Le Hur. He held postdoctoral positions at the Karlsruhe Institute of Technology (KIT) and at the University of Minnesota.

 

Zoom Meeting
https://desy.zoom.us/j/63690427429?pwd=hdhBmuaJeSfSkPjabkeYpG3iWUAXNd.1

Meeting-ID: 636 9042 7429
Kenncode: 203493