Designing Efficient Programmable Quantum Circuits

TL;DR

This paper introduces new quantum circuit schemes that enable efficient simulation of any operator by setting circuit angles based on matrix elements, with favorable classical and quantum complexity properties.

Contribution

The paper presents two general programmable quantum circuit schemes that efficiently simulate any operator, including non-unitary matrices, with fixed circuit designs and minimal classical computation.

Findings

Circuits can simulate any operator by setting angles from matrix elements.

Classical complexity of the circuits is low.

Quantum complexity is comparable to non-general circuits.

Abstract

Constructing general programmable circuits to be able to run any given unitary operator efficiently on a quantum processor is of fundamental importance. We present a new quantum circuit design technique resulting two general programmable circuit schemes. The circuit schemes can be used to simulate any given operator by setting the angle values in the circuit. This provides a fixed circuit design whose angles are determined from the elements of the given matrix, which can be non-unitary, in an efficient way. We also give both classical and quantum complexity analysis for these circuits and show that the circuits require a few classical computations, and the quantum complexities of them are almost the same as non-general circuits.