US 11,816,535 B1
Multi-state qubit readout with permutation sequences
Kevin Joseph Satzinger, Goleta, CA (US); Julian Shaw Kelly, Santa Barbara, CA (US); Paul Victor Klimov, Santa Barbara, CA (US); and Alexander Nikolaevich Korotkov, Riverside, CA (US)
Assigned to GOOGLE LLC, Mountain View, CA (US)
Filed by Google LLC, Mountain View, CA (US)
Filed on Dec. 2, 2020, as Appl. No. 17/109,448.
Claims priority of provisional application 62/948,365, filed on Dec. 16, 2019.
Claims priority of provisional application 62/942,946, filed on Dec. 3, 2019.
Int. Cl. G06N 10/00 (2022.01); G06F 15/16 (2006.01); B82Y 10/00 (2011.01)
CPC G06N 10/00 (2019.01) [B82Y 10/00 (2013.01); G06F 15/16 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for determining average occupation of quantum states of one or more qubits in a quantum computer, each qubit comprising three or more quantum states, the method comprising:
for each of a plurality of shuffling sequences:
applying, by the quantum computer, one or more quantum gates to the one or more qubits to execute a quantum algorithm;
applying, by the quantum computer, a shuffling sequence to the one or more qubits; and
measuring, using a readout apparatus, the state of the one or more qubits to determine a readout state; and
determining, by a classical computer or the quantum computer, an average occupation for one or more of the quantum states of the one or more qubits using the readout states for each of the shuffling sequences,
wherein the readout states each correspond to a state in a subset of the quantum states of the one or more qubits; and
wherein the plurality of shuffling sequences comprises one or more sequences for exchanging the population of two or more quantum states in the one or more qubits.