Phase gadget synthesis for shallow circuits

Alexander Cowtan, Silas Dilkes, Ross Duncan, Will Simmons, Seyon Sivarajah

Research output: Contribution to journalArticle

Abstract

We give an overview of the circuit optimisation methods used by tket, a compiler system for quantum software developed by Cambridge Quantum Computing Ltd. We focus on a novel technique based around phase gadgets, a family of multi-qubit quantum operations which occur naturally in a wide range of quantum circuits of practical interest. The phase gadgets have a simple presentation in the ZX-calculus, which makes it easy to reason about them. Taking advantage of this, we present an efficient method to translate the phase gadgets back to CNOT gates and single qubit operations suitable for execution on a quantum computer with significant reductions in gate count and circuit depth. We demonstrate the effectiveness of these methods on a quantum chemistry benchmarking set based on variational circuits for ground state estimation of small molecules.

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Networks (circuits)
Quantum chemistry
Quantum computers
Benchmarking
State estimation
Ground state
Molecules

Keywords

  • quantum computation
  • noisy intermediate-scale quantum
  • quantum software
  • compilations

Cite this

Cowtan, Alexander ; Dilkes, Silas ; Duncan, Ross ; Simmons, Will ; Sivarajah, Seyon. / Phase gadget synthesis for shallow circuits. In: Electronic Proceedings in Theoretical Computer Science. 2019.
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Phase gadget synthesis for shallow circuits. / Cowtan, Alexander; Dilkes, Silas; Duncan, Ross; Simmons, Will; Sivarajah, Seyon.

In: Electronic Proceedings in Theoretical Computer Science, 10.06.2019.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Phase gadget synthesis for shallow circuits

AU - Cowtan, Alexander

AU - Dilkes, Silas

AU - Duncan, Ross

AU - Simmons, Will

AU - Sivarajah, Seyon

PY - 2019/6/10

Y1 - 2019/6/10

N2 - We give an overview of the circuit optimisation methods used by tket, a compiler system for quantum software developed by Cambridge Quantum Computing Ltd. We focus on a novel technique based around phase gadgets, a family of multi-qubit quantum operations which occur naturally in a wide range of quantum circuits of practical interest. The phase gadgets have a simple presentation in the ZX-calculus, which makes it easy to reason about them. Taking advantage of this, we present an efficient method to translate the phase gadgets back to CNOT gates and single qubit operations suitable for execution on a quantum computer with significant reductions in gate count and circuit depth. We demonstrate the effectiveness of these methods on a quantum chemistry benchmarking set based on variational circuits for ground state estimation of small molecules.

AB - We give an overview of the circuit optimisation methods used by tket, a compiler system for quantum software developed by Cambridge Quantum Computing Ltd. We focus on a novel technique based around phase gadgets, a family of multi-qubit quantum operations which occur naturally in a wide range of quantum circuits of practical interest. The phase gadgets have a simple presentation in the ZX-calculus, which makes it easy to reason about them. Taking advantage of this, we present an efficient method to translate the phase gadgets back to CNOT gates and single qubit operations suitable for execution on a quantum computer with significant reductions in gate count and circuit depth. We demonstrate the effectiveness of these methods on a quantum chemistry benchmarking set based on variational circuits for ground state estimation of small molecules.

KW - quantum computation

KW - noisy intermediate-scale quantum

KW - quantum software

KW - compilations

UR - https://arxiv.org/abs/1906.01734

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JO - Electronic Proceedings in Theoretical Computer Science

T2 - Electronic Proceedings in Theoretical Computer Science

JF - Electronic Proceedings in Theoretical Computer Science

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