Quantum mechanics

Algorithm

Voltage

Quantum computer

Engineering

Quantum error correction

Circuit extraction

Overhead (engineering)

Quantum circuit

Embedded system

Operating system

Computer science

Electronic circuit

Physics

Circuit design

Electronic engineering

Equivalent circuit

Quantum

Qubit

Electrical engineering

npj Quantum Information

We introduce maximum-likelihood fragment tomography (MLFT) as an improved circuit cutting technique for running clustered quantum circuits on quantum devices with a limited number of qubits. In addition to minimizing the classical computing overhead of circuit cutting methods, MLFT finds the most likely probability distribution for the output of a quantum circuit, given the measurement data obtained from the circuit’s fragments. We demonstrate the benefits of MLFT for accurately estimating the output of a fragmented quantum circuit with numerical experiments on random unitary circuits. Finally, we show that circuit cutting can estimate the output of a clustered circuit with higher fidelity than full circuit execution, thereby motivating the use of circuit cutting as a standard tool for running clustered circuits on quantum hardware.

Quantum circuit cutting with maximum-likelihood tomography