Probabilistic computer fills gap between quantum and classical computers
The probabilistic computer is capable of solving 'Quantum' problems using less energy and space than classical computers.
Quantum computers are still years away from being used commonly. However, the classical computers we are using, are at the peak of their hardware and computing capabilities. So, you think we might have to wait until we can use quantum computers again? No.
Engineers at Purdue University and Tohoku University in Japan have built hardware that can be assembled to form a probabilistic computer. Computers that will be better than the classical computers but not as costly as Quantum computers.
Let’s get into more detail about it.
All About the Hardware:
The fundamental units on these computers are called p-bits. Computers work on instructions that are a combination of zero and one - binary signals. In classical computers these instructions are sent through transistors.
Quantum computers use q-bits that can be both zero and one at the same time. But, in probabilistic computers, the p-bits can be either zero or one at any given point of time. It is also capable of fluctuating between these two rapidly. Classic computers use a combination of both zero and one to send information.
Memory and its compilation:
The memory found on probabilistic computers is a modified version of RAM called MRAM, where M stands for 'Magnetoresistive'. MRAMs are used in a few of the computers today; they use the orientation of magnets (south and north) to create a state of resistance related to zero and one. Simply put, it can show resistance to one of the bits depending on the orientation of the magnet used in it.
Researchers from Tohoku University altered an MRAM device to make p-bits fluctuate on the computer. Other researchers from Purdue university combined the MRAM with a transistor to build a three-dimensional unit whose fluctuations could be controlled. Eight of such p-bits were interconnected to build a probabilistic computer.
How is it different from Quantum computers?
Quantum computers need a very low temperature to operate whereas the p-bits found in probabilistic computer can work at room temperature.
What can it be used for?
The device will be capable of solving problems related to drug research, encryption and cybersecurity, financial services, data analysis and supply chain logistics. Many of these problems were expected to be solved by Quantum computers.
How is it better than classical computers?
The probabilistic computer is capable of solving 'Quantum' problems like breaking down, or factoring, numbers such as 35,161 and 945 - also called integer factorisation. These problems can also be solved by classical computers but probabilistic computers are expected to solve these problems using less energy and space.
“On a chip, this circuit would take up the same area as a transistor, but perform a function that would have taken thousands of transistors to perform. It also operates in a manner that could speed up calculation through the parallel operation of a large number of p-bits,” said Ahmed Zeeshan Pervaiz, a Ph.D. student in electrical and computer engineering at Purdue.
Researchers suggests that hundreds of p-bits will be required to solve bigger problems but 'that’s not too far off'. “In the near future, p-bits could better help a machine to learn like a human does or optimize a route for goods to travel to market,” said Kerem Camsari, a Purdue postdoctoral associate in electrical and computer engineering.
The concept behind it
The concept of probabilistic computer was laid by a research team lead by Supriyo Datta, a professor of Electrical and Computer Engineering at Purdue in 2017. “There is a useful subset of problems solvable with qubits that can also be solved with p-bits. You might say that a p-bit is a ‘poor man’s qubit,’” Datta said.