SyReC Synthesizer: An MQT tool for synthesis of reversible circuits

Reversible circuits form the backbone for many promising emerging technologies such as quantum computing, low power/adiabatic design, encoder/decoder devices, and several other applications. In the recent years, the scalable synthesis of such circuits has gained significant attention. In this work, we present the SyReC Synthesizer, a synthesis tool for reversible circuits based on the hardware description language SyReC. SyReC allows to describe reversible functionality at a high level of abstraction. The provided SyReC Synthesizer then realizes this functionality in a push-button fashion. Corresponding options allow for a trade-off between the number of needed circuit signals/lines (relevant, e.g., for quantum computing in which every circuit line corresponds to a qubit) and the respectively needed gates (corresponding to the circuit's costs). Furthermore, the tool allows to simulate the resulting circuit as well as to determine the gate costs of it. The SyReC Synthesizer is available as an open-source software package at https://github.com/cda-tum/syrec as part of the Munich Quantum Toolkit (MQT).Comment: 6 pages, 3 figures, Software Impacts Journa

Synthesis of Topological Quantum Circuits

Topological quantum computing has recently proven itself to be a very powerful model when considering large- scale, fully error corrected quantum architectures. In addition to its robust nature under hardware errors, it is a software driven method of error corrected computation, with the hardware responsible for only creating a generic quantum resource (the topological lattice). Computation in this scheme is achieved by the geometric manipulation of holes (defects) within the lattice. Interactions between logical qubits (quantum gate operations) are implemented by using particular arrangements of the defects, such as braids and junctions. We demonstrate that junction-based topological quantum gates allow highly regular and structured implementation of large CNOT (controlled-not) gate networks, which ultimately form the basis of the error corrected primitives that must be used for an error corrected algorithm. We present a number of heuristics to optimise the area of the resulting structures and therefore the number of the required hardware resources.Comment: 7 Pages, 10 Figures, 1 Tabl

Depth-Optimized Reversible Circuit Synthesis

In this paper, simultaneous reduction of circuit depth and synthesis cost of reversible circuits in quantum technologies with limited interaction is addressed. We developed a cycle-based synthesis algorithm which uses negative controls and limited distance between gate lines. To improve circuit depth, a new parallel structure is introduced in which before synthesis a set of disjoint cycles are extracted from the input specification and distributed into some subsets. The cycles of each subset are synthesized independently on different sets of ancillae. Accordingly, each disjoint set can be synthesized by different synthesis methods. Our analysis shows that the best worst-case synthesis cost of reversible circuits in the linear nearest neighbor architecture is improved by the proposed approach. Our experimental results reveal the effectiveness of the proposed approach to reduce cost and circuit depth for several benchmarks.Comment: 13 pages, 6 figures, 5 tables; Quantum Information Processing (QINP) journal, 201

The Transforming Method Between Two Reversible Functions

This paper presents an original method of designing some special reversible circuits. This method is intended for the most popular gate set with three types of gates CNT (Control, NOT and Toffoli). The presented algorithm is based on two types of cascades with these reversible gates. The problem of transformation between two reversible functions is solved. This method allows to find optimal reversible circuits. The paper is organized as follows. Section 1 and 2 recalls basic concepts of reversible logic. Especially the two types of cascades of reversible function are presented. In Section 3 there is introduced a problem of analysis of the cascades. Section 4 describes the method of synthesis of the optimal cascade for transformation of the given reversible function into another one