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

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.