Analysis and Evaluation of Quantum Compilers


Quantum computers have the potential to solve specific tasks faster than the classical computational systems. There is currently a lot of effort to develop algorithms that take advantage of this type of quantum speedup. Today’s quantum computers, often called noisy intermediate-scale quantum (NISQ) hardware, are prone to noise and have too few qubits for effective error correction. They also have restrictions on which operations can be applied to which qubits. Quantum compilers are necessary to abstract the constraints of NISQ devices. This thesis presents an in-depth analysis and evaluation of quantum compilers. The study focuses on three commonly used quantum compilers: Qiskit, TKET, and BQSKit, each known for their unique approaches to compile and optimize quantum circuits. It is investigated how the quantum compilers behave depending on the chosen level of optimization. In order to address this question, an evaluation framework is developed which allows the evaluation of different quantum compilers by measuring circuit properties of the circuits compiled for defined backends. The evaluation is conducted with varying optimization levels of the compilers. It can be shown that the highest level of optimization does not necessary produce the best circuits in terms of circuit depth and overall gate count.