Characterization of how dissipation and dephasing errors accumulate in quantum computers

• Published in: EPJ quantum technology Vol. 2; no. 1; p. 1
• Main Authors: Gulliksen, Jake, Dasari, Durga Bhaktavatsala Rao, Mølmer, Klaus
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.12.2015; Springer Nature B.V
• Subjects: Nanotechnology and Microengineering; Physics; Physics and Astronomy; Quantum Information Technology; Quantum Physics; Quantum simulations; Spintronics; quantum tomography; Monte Carlo wavefunction; Rydberg atoms
• ISSN: 2196-0763; 2196-0763
• DOI: 10.1140/epjqt17

We study the achievements of quantum circuits comprised of several one- and two-qubit gates subject to dissipation and dephasing. Quantum process matrices are determined for the basic one- and two-qubit gate operations and concatenated to yield the process matrix of the combined quantum circuit. Examples are given of process matrices obtained by a Monte Carlo wavefunction analysis of Rydberg blockade gates in neutral atoms. Our analysis is ideally suited to compare different implementations of the same process. In particular, we show that the three-qubit Toffoli gate facilitated by the simultaneous interaction between all atoms may be accomplished with higher fidelity than a concatenation of one- and two-qubit gates.