136 citations · 857 across the 33 of their papers we have counts for
33 papers
Pulse-optimised circuit elements for scalable and noise-resilient quantum chemistry
Henrik Gothen, Christopher K. Long, Djamila Hiller +4
Useful chemistry calculations on near-term quantum processors are hindered by current algorithmic runtimes. We develop a methodology to significantly reduce these runtimes. Typical…
Hardware-Tailored Resource Estimation for Magic-State Distillation on Silicon Spin Qubits
Songqinghao Yang, Christopher K. Long, Rubén M. Otxoa +3
We present a resource analysis for generating high-fidelity logical magic states on silicon spin-qubit platforms. We consider a range of architectures, including a shuttling-based…
Quantum metrology enhanced by effective time reversal
Yu-Xin Wang, Flavio Salvati, David R. M. Arvidsson-Shukur +3
Quantum metrology involves the application of quantum resources to enhance measurements. Several communities have developed quantum-metrology strategies that leverage effective tim…
Theory of direct measurement of the quantum pseudo-distribution via its characteristic function
Andrew N. Jordan, David R. M. Arvidsson-Shukur, Aephraim M. Steinberg
We propose a method for directly measuring the quantum mechanical pseudo-distribution of observable properties via its characteristic function. Vandermonde matrices of the eigenval…
QuantGraph: A Receding-Horizon Quantum Graph Solver
Pranav Vaidhyanathan, Aristotelis Papatheodorou, David R. M. Arvidsson-Shukur +3
Dynamic programming is a cornerstone of graph-based optimization. While effective, it scales unfavorably with problem size. In this work, we present QuantGraph, a two-stage quantum…
Superconducting-antiqubit simulation enables optimal phase estimation via unitary inversion
Xingrui Song, Surihan Sean Borjigin, Flavio Salvati +4
A positron is equivalent to an electron traveling backward through time. Casting transmon superconducting qubits as akin to electrons, we simulate a positron with a transmon subjec…
Risk-minimizing states for the quantum-phase-estimation algorithm
Joseph G. Smith, Crispin H. W. Barnes, David R. M. Arvidsson-Shukur
The quantum-phase-estimation algorithm (QPEA) is widely used to find estimates of unknown phases. The original algorithm relied on an input state in a uniform superposition of all…
Minimal evolution times for fast, pulse-based state preparation in silicon spin qubits
Christopher K. Long, Nicholas J. Mayhall, Sophia E. Economou +5
Standing as one of the most significant barriers to reaching quantum advantage, state-preparation fidelities on noisy intermediate-scale quantum processors suffer from quantum-gate…
Properties and Applications of the Kirkwood-Dirac Distribution
David R. M. Arvidsson-Shukur, William F. Braasch, Stephan De Bievre +6
Recent years have seen the Kirkwood-Dirac (KD) distribution come to the forefront as a powerful quasi-probability distribution for analysing quantum mechanics. The KD distribution…
Agnostic Phase Estimation
Xingrui Song, Flavio Salvati, Chandrashekhar Gaikwad +3
The goal of quantum metrology is to improve measurements' sensitivities by harnessing quantum resources. Metrologists often aim to maximize the quantum Fisher information, which bo…
Dynamic-ADAPT-QAOA: An algorithm with shallow and noise-resilient circuits
Nikola Yanakiev, Normann Mertig, Christopher K. Long +1
The quantum approximate optimization algorithm (QAOA) is an appealing proposal to solve NP problems on noisy intermediate-scale quantum (NISQ) hardware. Making NISQ implementations…
Layering and subpool exploration for adaptive Variational Quantum Eigensolvers: Reducing circuit depth, runtime, and susceptibility to noise
Christopher K. Long, Kieran Dalton, Crispin H. W. Barnes +2
Adaptive variational quantum eigensolvers (ADAPT-VQEs) are promising candidates for simulations of strongly correlated systems on near-term quantum hardware. To further improve the…
Compression of metrological quantum information in the presence of noise
Flavio Salvati, Wilfred Salmon, Crispin H. W. Barnes +1
In quantum metrology, information about unknown parameters is accessed by measuring probe states . In experimental settings where co…
Characterizing the geometry of the Kirkwood-Dirac positive states
Christopher Langrenez, David R. M. Arvidsson-Shukur, Stephan De Bièvre
The Kirkwood-Dirac (KD) quasiprobability distribution can describe any quantum state with respect to the eigenbases of two observables and . KD distributions behave similarl…
An adaptive Bayesian quantum algorithm for phase estimation
Joseph G. Smith, Crispin H. W. Barnes, David R. M. Arvidsson-Shukur
Quantum-phase-estimation algorithms are critical subroutines in many applications for quantum computers and in quantum-metrology protocols. These algorithms estimate the unknown st…
Quantifying the effect of gate errors on variational quantum eigensolvers for quantum chemistry
Kieran Dalton, Christopher K. Long, Yordan S. Yordanov +4
Variational quantum eigensolvers (VQEs) are leading candidates to demonstrate near-term quantum advantage. Here, we conduct density-matrix simulations of leading gate-based VQEs fo…
Nonclassical advantage in metrology established via quantum simulations of hypothetical closed timelike curves
David R. M. Arvidsson-Shukur, Aidan G. McConnell, Nicole Yunger Halpern
We construct a metrology experiment in which the metrologist can sometimes amend her input state by simulating a closed timelike curve, a worldline that travels backward in time. T…
An iterative quantum-phase-estimation protocol for near-term quantum hardware
Joseph G. Smith, Crispin H. W. Barnes, David R. M. Arvidsson-Shukur
Given applications of a unitary operation with an unknown phase , a large-scale fault-tolerant quantum system can {reduce} an estimate's {error} scaling from…
Room temperature coherent control of protected qubit in hexagonal boron nitride
Andrew J. Ramsay, Reza Hekmati, Charlie J. Patrickson +4
Spin defects in foils of hexagonal boron nitride are an attractive platform for magnetic field imaging, since the probe can be placed in close proximity to the target. However, as…
Negative quasiprobabilities enhance phase estimation in quantum-optics experiment
Noah B. Lupu-Gladstein, Batuhan Y. Yilmaz, David R. M. Arvidsson-Shukur +4
Operator noncommutation, a hallmark of quantum theory, limits measurement precision, according to uncertainty principles. Wielded correctly, though, noncommutation can boost precis…
Molecular excited state calculations with the QEB-ADAPT-VQE
Yordan S. Yordanov, Crispin H. W. Barnes, David R. M. Arvidsson-Shukur
Calculations of molecular spectral properties, like photodissociation rates and absorption bands, rely on knowledge of the excited state energies of the molecule of interest. Proto…
Hamiltonian singular value transformation and inverse block encoding
Seth Lloyd, Bobak T. Kiani, David R. M. Arvidsson-Shukur +5
The quantum singular value transformation is a powerful quantum algorithm that allows one to apply a polynomial transformation to the singular values of a matrix that is embedded a…
Quantum Learnability is Arbitrarily Distillable
Joe H. Jenne, David R. M. Arvidsson-Shukur
Quantum learning (in metrology and machine learning) involves estimating unknown parameters from measurements of quantum states. The quantum Fisher information matrix can bound the…
Qubit-excitation-based adaptive variational quantum eigensolver
Yordan S. Yordanov, V. Armaos, Crispin H. W. Barnes +1
Molecular simulations with the variational quantum eigensolver (VQE) are a promising application for emerging noisy intermediate-scale quantum computers. Constructing accurate mole…