Hi all,
Tomorrow Caroline Tornow will tell us about her thesis "Error-mitigated circuit knitting with classical communication". See below for the abstract. The talk will take place at 2pm in HIT E 41.1
Best,
Ladina
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Title:
Error-mitigated circuit knitting with classical communication
Abstract:
Large-scale fault-tolerant quantum computers are still out of reach. Furthermore, it is a key challenge to develop error mitigation methods for noisy quantum devices and run applications on the limited number of qubits. Circuit knitting allows the simulation of a quantum computer with more qubits than are physically available, however, at the expense of a simulation overhead. Here, a large quantum circuit is partitioned into multiple fragments that fit on devices with fewer qubits. In this work, we study a variant of this technique, called circuit knitting with classical communication [1] which employs classical communication between the circuit fragments. Naturally, circuit knitting with classical communication requires measurements which are carried out mid-circuit and, based on their outcomes, trigger quantum operations. Due to inevitable qubit idling times, these dynamic quantum circuits are currently more prone to noise than quantum circuits consisting only of unitary gates. The dominant noise sources are dephasing and quantum crosstalk.
In this talk, we introduce circuit knitting with classical communication and its implementation on a noisy quantum computer. We present two techniques to suppress and mitigate noise, dynamical decoupling and zero-noise extrapolation, and show how they can be tailored to dynamic quantum circuits. Using these techniques, we demonstrate error-mitigated circuit knitting with classical communication for graph-state circuits. Our results indicate that error suppression and mitigation make quantum applications involving dynamic quantum circuits, such as circuit knitting, feasible on currently available noisy quantum computers.
[1] C. Piveteau and D. Sutter, “Circuit knitting with classical communication”, IEEE Transactions on Information Theory (2023)