Over the past few years, technological advances have literally transformed our lives and revolutionised the world. Cellphones and laptops available at our fingertips have surpassed well beyond what anyone could have imagined they could do when the first home computers were released in the 1970s. However, at the core of these devices, not much has changed – says University Distinguished Professor of Physics, Arun Bansil at Northeastern University.
His new research focuses on new ways to design quantum information systems, which could revolutionise data encryption, enable new medical treatments, and more accurately model the changing climate. Typical computers store information and make calculations using a bit, the smallest unit of data in a computer.“To make more powerful computers, we have simply added more bits. In that sense, computing in the last 50 years, its underlying principle has not changed,” said Bansil.
The basis of his research revolves around something called a quantum bit, or qubit, for short. Quantum computers promise to provide a more efficient way to process large amounts of information, opening the door to “an entirely new generation of technologies, sensors, and communications systems which are completely outside the domain of current thinking,” Bansil said.
However, it’s not really that simple. Understanding the qubit requires you to perform some mental gymnastics. Qubits perform calculations based on the probability of an object’s state before it is measured. Rather than having defined positions as the bit, quantum bits stay in a mixed ‘superposition’ such as the spin of an electron or the polarisation of a photon.
“As you add more qubits, things get weirder. Qubits can become entangled with each other. This phenomenon, which Albert Einstein famously dismissed as ‘spooky action at a distance,’ occurs when two particles are so deeply linked that changing one instantly changes the other, even if it isn’t nearby. A quantum computer can harness this ability to increase its computing power,” he adds.
A quantum computer can evaluate multiple possibilities to complex problems simultaneously and come up with an answer much faster. That is if researchers can get one to work. “This is a new frontier,” Bansil said. “You really have a fundamental change in the underlying paradigm from a classical bit to something that, in principle, is capable of much more information.”