3D illustration of a quantum computing system. Credit: James Thew / Alamy Stock Photo

Physicists have shown that it is possible to prove principles of quantum mechanics such as the superposition principle and Born rule by running experiments on a quantum computer1.

The superposition principle postulates that quantum objects may behave as waves and an object is in all possible states at the same time, until it is measured. The Born rule is a simple calculation of the probability of a particle that may exist at a given location along its wave function. Physicists at the Raman Research Institute in Bangalore wanted direct experimental proof for these principles of quantum mechanics using a quantum computer.

They performed two tests – the Peres and the Sorkin tests. They developed new algorithms and quantum machine code to run the tests on a quantum computer that contains superconducting circuits and operates at an extremely low temperature. The circuits processed information in superconducting quantum bits or qubits. A qubit can be 0 as well as 1, or a superposition of both.

The Sorkin test probed the probabilistic aspect of the Born rule and the Peres test checked the correctness of the superposition principle.

Both tests were performed on the same computer, separately and jointly, to reduce the possibility of biases arising from a tailored experimental set-up. The researchers, led by Urbasi Sinha, proved that quantum mechanics has an underlying mathematical structure based on complex numbers.

The researchers say the algorithms could be applied to different quantum computer architectures, to confirm their results independently. It is also possible to use these tests as a benchmark to evaluate how well a quantum computer performs, they add.