P-Bits: Bridging the Gap Between Standard Bits and Q-Bits Featured

Researchers introduce probabilistic bits, which have the potential to advance quantum computing and machine learning using existing technology.

quantum bits

Digital electronics use standard bits that are stored using well-developed technology. In comparison, quantum computing uses quantum bits, or q-bits, that need to be stored in quantum storage devices where physical implementations remain a major obstacle preventing the technology’s success.

Camsari et al. introduce the concept of probabilistic bits, or p-bits, to bridge the gap and act as an intermediate between standard bits and q-bits. p-bits are classical entities that fluctuate rapidly between 0 and 1—they can be physically represented by unstable low barrier magnets.

Lead author Kerem Camsari said that p-bits can be considered “the poor man’s q-bit” because they can be stored and processed using existing electronics and can emulate certain properties of q-bits. For example, the researchers used the circuit simulator SPICE to test p-circuits they designed. The results of their simulations of quantum annealing—a type of quantum computing—were similar to those obtained with quantum annealers, which suggests that a network of p-bits can approximate a network of q-bits.

In addition to quantum computing, p-bits may have applications in machine learning, which is another active field that could benefit from using highly tailored hardware for performing probabilistic calculations. p-bits are similar to the binary stochastic neurons used in machine learning, which could make them effective hardware accelerators.

The authors also argue that one way to implement p-bits in existing CMOS technologies can be through the spin-Hall effect or magneto-electric effect present in modern RAM technology. Next, they plan to further explore the extent to which a p-bit can function as “a poor man’s q-bit.”