Scientists have employed quantum computers for the first time for a novel purpose, going beyond the commonly recognised usage of quantum computers —- completing specific tasks at an exponentially quicker rate than classical computers. They have actually tested the very underpinnings of the theory on which their study is built using modern computers.
Quantum mechanics is founded on experiments, just like any other physical theory. Experiments are used to justify some assumptions from which the entire theory can be inferred logically. While a big portion of the scientific community is focused on developing quantum computing devices, another group is focused on doing precise testing of fundamental parts of quantum theory.
Quantum computers to perform precision
In collaborative study, a group of scientists from the Raman Research Institute (RRI), an autonomous institute of the Department of Science and Technology, used quantum computers to perform precision Sorkin and Peres tests on key parts of quantum theory. The first is a test of quantum mechanics’ probabilistic aspect, which helps calculate the likelihood of events occurring, and the second is a test of an aspect of the superposition principle, which expresses the fact that quantum objects can behave as waves — throwing two stones in a pond produces a wave pattern that is the sum of two waves.
During the Quantum Frontiers and Fundamentals (QFF 2020) conference organised by RRI Bangalore in January 2020, Professor Urbasi Sinha of RRI Bangalore and conference delegate Prof. Lorenzo Macconne of the University of Pavia, Italy began collaborating. Prof. Sinha and her postdoc explored the possibility of performing experiments on quantum computers with Prof. Macconne, a quantum information theory expert, over the next two years. Prof. Sinha, with long-standing expertise and contributions in the domain of precision tests of quantum mechanics, and her postdoc explored the possibility of performing experiments on quantum computers with Prof. Macconne, an expert on quantum information theory.
The use of a quantum computer to perform tests of crucial quantum principles in research published as a rapid communication letter in the journal Physical Review Research has naturally resulted in the emergence of an entirely new research direction for the physics community that unifies diverse research disciplines under one unifying umbrella.
Quantum computers are scalable quantum systems, therefore they might be used to create a universally programmable quantum experiment setting. A quantum circuit, which functions as a low-level programme for quantum computers, could serve as a Rosetta stone, allowing experiments to be translated from one physical system to another.
As a corollary, the researchers have demonstrated that quantum mechanics is correct, and that the tests may be used to assess how effectively a quantum computer functions. “By using the basic foundations of quantum theory as the benchmarking tool, our method gives a great way to construct well-defined benchmarks for quantum computers so that we can know exactly how error-prone they are,” stated Professor Sinha.