An 8K-Spin Ising Machine IC with Reconfigurable Many-Body Spin Interactions and Limitless Multichip Extension

This work presents an Ising machine chip featuring 8K spins and up to 31 reconfigurable two- and three-body interactions for each spin. The proposed architecture supports building a larger system with limitless 1-dimensional extension, where multiple chips are connected in a chain by a serial interface while each chip is processing in parallel. The proposed Ising machine, implemented in 28nm CMOS, is verified in a system including four chips. Tested on 3SAT problems with 32,760 variables, the system achieves the largest problem capacity at both the chip level and the system level.