US 12,169,673 B2
Toffoli gate preparation for a quantum hardware system comprising hybrid acoustic-electrical qubits
Christopher Chamberland, Pasadena, CA (US); Fernando Brandao, Pasadena, CA (US); and Earl Campbell, Cambridge (GB)
Assigned to Amazon Technologies, Inc., Seattle, WA (US)
Filed by Amazon Technologies, Inc., Seattle, WA (US)
Filed on Oct. 7, 2022, as Appl. No. 18/045,102.
Application 18/045,102 is a division of application No. 17/098,237, filed on Nov. 13, 2020, granted, now 11,468,219.
Prior Publication US 2023/0080126 A1, Mar. 16, 2023
Int. Cl. G06F 30/3308 (2020.01); G06F 8/20 (2018.01); G06N 10/00 (2022.01); G06F 111/10 (2020.01); G06F 119/02 (2020.01)
CPC G06F 30/3308 (2020.01) [G06F 8/20 (2013.01); G06N 10/00 (2019.01); G06F 2111/10 (2020.01); G06F 2119/02 (2020.01)] 20 Claims
OG exemplary drawing
 
1. A method for simulating a Toffoli gate encoded in arbitrary Calderbank-Shor-Steane codes, the method comprising:
preparing computational basis states in a fault-tolerant manner by applying a STOP algorithm to determine when syndrome measurements of stabilizers of a repetition code for the computational basis states can be stopped such that a probability of faults for the computational basis states are below a threshold level;
transversally applying a CNOT gate to the prepared computational basis states to prepare a |ψ1custom character state;
measuring a Clifford stabilizer gA for the |ψ1custom character state, and applying a logical Z correction if the measurement outcome for the Clifford stabilizer gA is −1, wherein measuring the Clifford stabilizer gA and applying the logical Z correction based on a measurement outcome of the Clifford stabilizer ga prepares a state |ψoutcustom character;
repeating the Clifford stabilizer gA measurement for the |ψ1custom character state a threshold number of times;
preparing a Toffoli magic state in response to determining the Clifford stabilizer gA measurements are trivial; and
applying a sequence of Clifford gates to a logical input state |ψcustom characterL and the prepared Toffoli magic state to simulate a logical Toffoli gate, wherein Clifford error corrections are applied to outputs of the sequence of Clifford gates applied to logical inputs.