RRI technique yields certified randomness with one qubit, Pg10

Key Highlights:

• Researchers at the Raman Research Institute have successfully generated certified random numbers using a single qubit on IBM's quantum computers.
• The team utilized the Leggett-Garg inequality (LGI) to certify the randomness, demonstrating that current quantum devices can perform tasks impossible for classical machines.
• The experiments involved building simple quantum circuits on IBM’s superconducting quantum computers and measuring them at three different times.
• The study highlights the importance of error-mitigation tools in making quantum hardware reliable and shows how quantum mechanics can benefit society today.

Detailed Insights:

• Conventional computers use pseudorandom number generators, which are predictable and pose security risks in applications like cryptography.
• True random number generators rely on physical processes but can degrade over time and require trust in manufacturers.
• Quantum physics offers a solution through the principle that some outcomes, like the spin of an electron, are fundamentally random.
• The Leggett-Garg inequality (LGI) allows for the certification of randomness by comparing measurements performed at different times on the same system.
• The team's experiments on IBM's Brussels backend showed consistent violations of the LGI, confirming the randomness of the generated bits.
• This research demonstrates that secure random numbers can be generated on existing quantum computers without elaborate setups, benefiting data encryption, secure communications, and scientific simulations.
• The study also contributes to foundational physics by validating quantum theory in a new setting and providing a tool to benchmark qubits individually.

Key Concepts Involved:

• Qubit: A quantum bit, the basic unit of information in a quantum computer.
• Leggett-Garg inequality (LGI): An inequality used to test whether a system behaves in a quantum mechanical manner over time.
• Quantum computer: A computer that uses quantum-mechanical phenomena such as superposition and entanglement to perform calculations.