Skip to main content
Open Access Publications from the University of California

UC Santa Barbara

UC Santa Barbara Previously Published Works bannerUC Santa Barbara

Scalable Emulation of Sign-Problem-Free Hamiltonians with Room-Temperature p-bits

  • Author(s): Camsari, KY;
  • Chowdhury, S;
  • Datta, S
  • et al.

The growing field of quantum computing is based on the concept of a q-bit, which is a delicate superposition of 0 and 1, requiring cryogenic temperatures for its physical realization along with challenging coherent coupling techniques for entangling them. By contrast, a probabilistic bit or a p-bit is a robust classical entity that fluctuates between 0 and 1 and can be implemented at room temperature using present-day technology. Here, we show that a probabilistic coprocessor built out of room-temperature p-bits can be used to accelerate simulations of a special class of quantum many-body systems that are sign-problem-free or "stoquastic," leveraging the well-known Suzuki-Trotter decomposition that maps a d-dimensional quantum many-body Hamiltonian to a d+1-dimensional classical Hamiltonian. This mapping allows an efficient emulation of a quantum system by classical computers and is commonly used in software to perform quantum Monte Carlo (QMC) algorithms. By contrast, we show that a compact, embedded magnetic tunnel junction (MTJ)-based coprocessor can serve as a highly efficient hardware accelerator for such QMC algorithms, providing an improvement in speed of several orders of magnitude compared to optimized CPU implementations. Using realistic device-level spice simulations, we demonstrate that the correct quantum correlations can be obtained using a classical p-circuit built with existing technology and operating at room temperature. The proposed coprocessor can serve as a tool to study stoquastic quantum many-body systems, overcoming challenges associated with physical quantum annealers.

Many UC-authored scholarly publications are freely available on this site because of the UC's open access policies. Let us know how this access is important for you.

Main Content
For improved accessibility of PDF content, download the file to your device.
Current View