Chisel-Q: Designing quantum circuits with a scala embedded language

Abstract

Abstract-We introduce Chisel-Q, a high-level functional language for generating quantum circuits. Chisel-Q permits quantum computing algorithms to be constructed using the metalanguage features of Scala and its embedded DSL Chisel. With Chisel-Q, designers of quantum computing algorithms gain access to high-level, modern language features and abstractions. We describe a synthesis flow that transforms Chisel-Q into an explicit quantum circuit in the Quantum Assembly Language (QASM) format. We also discuss several optimizations to reduce the generated hardware cost. The Chisel-Q tool includes resource and performance estimation which can be used to compare different implementations of the same functionality. We compare the output of the generic Chisel-Q synthesis flow with hand-tuned versions of well-known quantum circuits. . Although practical quantum computers are still on the horizon, research progress is steady: over the last decade, physicists have investigated a number of approaches to implementing quantum circuits [5,6], computer architects have investigated architectures for quantum computers [7,8], and mathematicians have explored how to express difficult computational problems as instances of quantum computing [9,10]. Unfortunately, techniques for expressing quantum algorithms are mostly limited to high-level mathematical expressions or low-level sequences of quantum gates [11]. More traditional programming languages have not yet surfaced that are capable of expressing and handling the idiosyncrasies of quantum computing. As a result, many of the time-honored techniques for abstraction, design, and debugging of classical algorithms are not available to the writer of quantum algorithms.

Hierarchical Synthesis of Quantum and Reversible Architectures

“…The library can be populated with circuits synthesized by the proposed method, or by any other method, permitting multilevel hierarchical synthesis of any depth. Parts of the library could be the synthesis output results of tools like [34,35] for the reversible case or tools like [1,9,15,16] for the quantum case by invoking these tools as back-end and passing them the parameters of the required parts (function type, input and output size). Another option could be the integration of the proposed method in the above mentioned tools.…”

“…adders or other arithmetic circuits), automatically synthesized by a synthesis method chosen by the user, or synthesized by the proposed method if a bottom up design is needed to handle a complex specification. To our knowledge only a few hierarchical synthesis method have been presented in the literature [1,9,16,34,35]. Our hierarchical synthesis method applies to both reversible and quantum circuits and eliminates intermediate bits/qubits without excessive ancilla usage.…”

“…The approaches of [1] (CTQG part of ScaffCC) don't reduce ancilla significantly and the connections between the modules must be done by the user in a description language (structural synthesis approach as opposed to our behavioral synthesis approach). On the other hand, Chisel-Q [16] and Quipper [9] exploit the globally applied Bennett's method on each block of the hierarchy and thus in general it requires more ancilla qubits.…”

Formal Verification of Quantum Algorithms Using Quantum Hoare Logic

“…In another direction, intensive research on quantum programming has been conducted in the last decade [16,45,51,53], as surveyed in [27,52]. In particular, several quantum programming languages have been defined and their compilers have been implemented, including Quipper [31], Scaffold [35], QWire [47], Microsoft's LIQUi| [25] and Q# [57], IBM's OpenQASM [22], Google's Cirq [30], ProjectQ [56], Chisel-Q [40], Quil [55] and Q |SI [39]. These research allow quantum programs to first run on an ideal simulator for testing, and then on physical devices [5].…”

Design and synthesis of efficient circuits for quantum computers

“…adders or other arithmetic circuits), automatically synthesized by a synthesis method chosen by the user, or synthesized by the proposed method if a bottom up design is needed to handle a complex specification. To our knowledge only a few hierarchical synthesis method have been presented in the literature [175,176,177,178,178]. The proposed hierarchical synthesis method applies to both reversible and quantum circuits and eliminates intermediate bits/qubits without excessive ancilla usage.…”