ALEXANDRIA, Va., Oct. 21 -- United States Patent no. 12,443,872, issued on Oct. 14, was assigned to Google LLC (Mountain View, Calif.).
"Measuring quantum state purity" was invented by Julian Shaw Kelly (Santa Barbara, Calif.), Zijun Chen (Santa Barbara, Calif.) and Sergio Boixo Castrillo (Rancho Palos Verdes, Calif.).
According to the abstract* released by the U.S. Patent & Trademark Office: "Methods, systems and apparatus for measuring quantum state purity. In one aspect, a method for determining an average purity of multiple output quantum states, wherein the multiple output quantum states correspond to applications of respective random quantum circuits of a same circuit depth to a same initial quantum state, the method including: obta...