English

Generating Randomness from a Computable, Non-random Sequence of Qubits

Information Theory 2020-05-04 v1 Logic in Computer Science math.IT Quantum Physics

Abstract

Nies and Scholz introduced the notion of a state to describe an infinite sequence of qubits and defined quantum-Martin-Lof randomness for states, analogously to the well known concept of Martin-L\"of randomness for elements of Cantor space (the space of infinite sequences of bits). We formalize how 'measurement' of a state in a basis induces a probability measure on Cantor space. A state is 'measurement random' (mR) if the measure induced by it, under any computable basis, assigns probability one to the set of Martin-L\"of randoms. Equivalently, a state is mR if and only if measuring it in any computable basis yields a Martin-L\"of random with probability one. While quantum-Martin-L\"of random states are mR, the converse fails: there is a mR state, x which is not quantum-Martin-L\"of random. In fact, something stronger is true. While x is computable and can be easily constructed, measuring it in any computable basis yields an arithmetically random sequence with probability one. I.e., classical arithmetic randomness can be generated from a computable, non-quantum random sequence of qubits.

Cite

@article{arxiv.2005.00207,
  title  = {Generating Randomness from a Computable, Non-random Sequence of Qubits},
  author = {Tejas Bhojraj},
  journal= {arXiv preprint arXiv:2005.00207},
  year   = {2020}
}

Comments

In Proceedings QPL 2019, arXiv:2004.14750

R2 v1 2026-06-23T15:13:57.956Z