The two-qubit singlet/triplet measurement is universal for quantum computing given only maximally-mixed initial states

TL;DR

This paper proves that a specific two-qubit measurement, the singlet/triplet measurement, can perform universal quantum computation starting from maximally mixed states, enabling a simple, reference frame independent quantum computing method.

Contribution

It establishes the universality of the singlet/triplet measurement for quantum computing with maximally mixed initial states, confirming the STP=BQP conjecture.

Findings

Proves the STP=BQP conjecture for the singlet/triplet measurement.

Shows the measurement's universality with maximally mixed states.

Provides a physically accessible, reference frame independent quantum computing approach.

Abstract

We prove the STP=BQP conjecture of Freedman, Hastings and Shokrian-Zini [1], namely that the two-qubit singlet/triplet measurement is quantum computationally universal given only an initial ensemble of maximally mixed single qubits. This provides a method for quantum computing that is fully rotationally symmetric (i.e. reference frame independent), using primitives that are both physically very-accessible and provably the simplest possible.