Efficient method for computing the maximum-likelihood quantum state from measurements with additive Gaussian noise

• Published in: Physical review letters Vol. 108; no. 7; p. 070502
• Main Authors: Smolin, John A, Gambetta, Jay M, Smith, Graeme
• Format: Journal Article
• Language: English
• Published: United States 17.02.2012

We provide an efficient method for computing the maximum-likelihood mixed quantum state (with density matrix ρ) given a set of measurement outcomes in a complete orthonormal operator basis subject to Gaussian noise. Our method works by first changing basis yielding a candidate density matrix μ which...