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Feature Article

Feature Article

Probabilistic Bits - p-bits

Bridging the gap between classical bits and quantum bits

Classical computing is based on a bit, a device that can be either a ‘0’ or a ‘1’, but not both at the same time, which switches only when an operation occurs. In contrast, quantum computing is based on a quantum bit (q-bit or qubit), a device that is represented as a quantum superposition of ‘0’ and ‘1’ at the same time. A third type of device, distinct from the other two, is a classical probabilistic bit or p-bit, which naturally fluctuates between ‘0’ and ‘1’. A research group at Purdue University, under the direction of Prof. Supriyo Datta, has shown how these types of p-bits can provide the basis for a type of probabilistic computing.

The authors suggest that these devices can be implemented using low-barrier magnetic memory cells similar to those in conventional memory technologies. They further indicate that the p-bit may represent a “poor-man’s qubit”, and that systems of p-bits can be used to address some problems that might otherwise seem to require quantum computing, such as quantum annealing. Furthermore, they can also be used as binary stochastic neurons for stochastic machine learning.

The paper, “P-Bits for Probabilistic Spin Logic”, by Kerem Cansari, Brian Sutton, and Supriyo Datta, is available here.

A brief overview of this work is available here.

A video presentation by Prof. Datta on this topic is available here.

Technology Spotlight

Technology Spotlight

The Computing Landscape of the 21st Century

The 4 tiers of future computing

At the recent International Workshop on Mobile Computing Systems and Applications (HotMobile 2019), held in Santa Cruz, California in February, Carnegie-Mellon Prof. Mahadev Satyanaryanan gave a keynote presentation on how future computing will be organized.

He emphasized that although computing technology is changing, the computing landscape is likely to be organized around 4 tiers, each with its own characteristic scale and power budget. The top tier comprises cloud computing in data centers, followed by a second tier of edge computers linked to the network. The third tier comprises small mobile devices, including the Internet of Things (IoT), powered by batteries. The final tier comprises networks of sensors, either passive or powered by energy harvesting.

The video of Prof. Satyanarayanan’s talk is available here.

The published conference paper is available here.

Videos of other HotMobile talks are available here.

The Proceedings of HotMobile 2019 is available here.