Quantum Depth Compression via Local Dynamic Circuits

TL;DR

Quantum Depth Compression (QDC) is a new compilation method that reduces quantum circuit depth and CNOT count by leveraging dynamic circuits and circuit restructuring, improving efficiency for non-Clifford gates.

Contribution

The paper introduces QDC, a novel framework that compresses quantum circuit depth and complexity without requiring expensive SWAP networks, using dynamic circuit techniques.

Findings

QDC reduces circuit depth for random Pauli-phasor circuits.

QDC lowers CNOT count compared to standard compilation methods.

QDC achieves depth linearity in non-Clifford gates.

Abstract

We present Quantum Depth Compression (QDC), a general compilation framework that utilizes dynamic circuits to reduce arbitrary quantum circuits to depth linear in the number of non-Clifford gates and to grid connectivity without the need for expensive SWAP-networks. The framework consists of pushing Clifford gates to the end of the circuit, resulting in a sequence of non-Clifford Pauli-phasors followed by an all Clifford sub-circuit, both of which are then reduced to constant depth via dynamic circuits. We show that applying QDC to random Pauli-phasor circuits lowers both their depth and CNOT count compared to a standard alternative compiler.