Classical Simulation of High Temperature Quantum Ising Models

Elizabeth Crosson and Sam Slezak have published a preprint demonstrating the efficiency of a classical algorithm for simulating high temperature thermal states of the generalized transverse Ising model.

This result follows a body of work on efficient simulations for specific types of transverse Ising models, in which it has been previously established that efficient classical algorithms exist for ferromagnetic transverse Ising models on any graph at any temperature as well as for certain 1-D models at any temperature.

This work extends the class of simulable models to those defined on an arbitrary graph with arbitrary couplings, given that the temperature is above a system dependent threshold. This threshold depends only on the degree of the interaction graph and the coupling strengths.

This work defines theoretical limitations for quantum annealing devices, ruling out the possibility of quantum advantage above certain operating temperatures.

In particular we calculate that for a device with a maximum interaction degree of 6 and a maximum coupling strength of 1GHZ the threshold of classical simulability is around 800mK.

CQuIC Welcomes Professor Elizabeth Crosson

Please join us in welcoming Elizabeth Crosson as a regular faculty member of CQuIC as she takes up her position as UNM Assistant Professor of Physics and Astronomy beginning September 1, 2018. Professor Crosson will also serve as a Project Director (PD) for CQuIC’s NSF grant-supported FRHTP project.

Prof. Elizabeth Crosson most recently worked as an IQIM Postdoctoral Scholar at the California Institute of Technology with John Preskill. Her research touches on several theoretical aspects of quantum computation, including adiabatic computation and optimization, quantum error correction, and Hamiltonian complexity. Her goal at UNM is to work with graduate students and continue doing research both on fundamental long-term questions in quantum information science, and also on developing immediate applications of the noisy intermediate-scale quantum computing devices that are now becoming available. She also plans to build a high-performance computing system dedicated to performing classical simulations of quantum systems. Prof. Crosson will be teaching a special topics course on quantum information in the Spring Semester 2019. Please welcome her to the CQuIC team.