Publications (117)
Quantum Simulation of Realistic Materials in First Quantization Using Non-local Pseudopotentials
Dominic W. Berry, Nicholas C. Rubin, Ahmed O. Elnabawy +5
This paper improves and demonstrates the usefulness of the first quantized plane-wave algorithms for the quantum simulation of electronic structure, developed by Babbush et al. and…
Quantum algorithm for linear matrix equations
Rolando D. Somma, Guang Hao Low, Dominic W. Berry +1
We describe an efficient quantum algorithm for solving the linear matrix equation AX+XB=C, where A, B, and C are given complex matrices and X is unknown. This is known as the Sylve…
The theory of variational hybrid quantum-classical algorithms
Jarrod R. McClean, Jonathan Romero, Ryan Babbush +1
Many quantum algorithms have daunting resource requirements when compared to what is available today. To address this discrepancy, a quantum-classical hybrid optimization scheme kn…
Reliably assessing the electronic structure of cytochrome P450 on today's classical computers and tomorrow's quantum computers
Joshua J. Goings, Alec White, Joonho Lee +6
An accurate assessment of how quantum computers can be used for chemical simulation, especially their potential computational advantages, provides important context on how to deplo…
Power of data in quantum machine learning
Hsin-Yuan Huang, Michael Broughton, Masoud Mohseni +4
The use of quantum computing for machine learning is among the most exciting prospective applications of quantum technologies. However, machine learning tasks where data is provide…
Is there evidence for exponential quantum advantage in quantum chemistry?
Seunghoon Lee, Joonho Lee, Huanchen Zhai +15
The idea to use quantum mechanical devices to simulate other quantum systems is commonly ascribed to Feynman. Since the original suggestion, concrete proposals have appeared for si…
Decoding quantum errors with subspace expansions
Jarrod R. McClean, Zhang Jiang, Nicholas C. Rubin +2
With the rapid developments in quantum hardware comes a push towards the first practical applications on these devices. While fully fault-tolerant quantum computers may still be ye…
Quantum error correction below the surface code threshold
Rajeev Acharya, Laleh Aghababaie-Beni, Igor Aleiner +246
Quantum error correction provides a path to reach practical quantum computing by combining multiple physical qubits into a logical qubit, where the logical error rate is suppressed…
Quantum simulation with sum-of-squares spectral amplification
Robbie King, Guang Hao Low, Ryan Babbush +2
We present sum-of-squares spectral amplification (SOSSA), a framework for improving quantum simulation relevant to low-energy problems. We show how SOSSA can be applied to problems…
Magic state cultivation on a superconducting quantum processor
Emma Rosenfeld, Craig Gidney, Gabrielle Roberts +292
Fault-tolerant quantum computing requires a universal gate set, but the necessary non-Clifford gates represent a significant resource cost for most quantum error correction archite…
Barren plateaus in quantum neural network training landscapes
Jarrod R. McClean, Sergio Boixo, Vadim N. Smelyanskiy +2
Many experimental proposals for noisy intermediate scale quantum devices involve training a parameterized quantum circuit with a classical optimization loop. Such hybrid quantum-cl…
Rapid initial state preparation for the quantum simulation of strongly correlated molecules
Dominic W. Berry, Yu Tong, Tanuj Khattar +8
Studies on quantum algorithms for ground state energy estimation often assume perfect ground state preparation; however, in reality the initial state will have imperfect overlap wi…
Matchgate Shadows for Fermionic Quantum Simulation
Kianna Wan, William J. Huggins, Joonho Lee +1
"Classical shadows" are estimators of an unknown quantum state, constructed from suitably distributed random measurements on copies of that state [Nature Physics 16, 1050-1057]. He…
Simulating challenging correlated molecules and materials on the Sycamore quantum processor
Ruslan N. Tazhigulov, Shi-Ning Sun, Reza Haghshenas +6
Simulating complex molecules and materials is an anticipated application of quantum devices. With strong quantum advantage demonstrated in artificial tasks, we examine how such adv…
Scaling and logic in the color code on a superconducting quantum processor
Nathan Lacroix, Alexandre Bourassa, Francisco J. H. Heras +212
Quantum error correction is essential for bridging the gap between the error rates of physical devices and the extremely low logical error rates required for quantum algorithms. Re…
Reinforcement Learning Control of Quantum Error Correction
Volodymyr Sivak, Alexis Morvan, Michael Broughton +296
Quantum error correction (QEC) is the primary strategy for protecting a quantum computer from the environment. Its prerequisite is that errors must remain sufficiently rare, which…
Characterizing Quantum Supremacy in Near-Term Devices
Sergio Boixo, Sergei V. Isakov, Vadim N. Smelyanskiy +6
A critical question for the field of quantum computing in the near future is whether quantum devices without error correction can perform a well-defined computational task beyond t…
Generative quantum advantage for classical and quantum problems
Hsin-Yuan Huang, Michael Broughton, Norhan Eassa +3
Recent breakthroughs in generative machine learning, powered by massive computational resources, have demonstrated unprecedented human-like capabilities. While beyond-classical qua…
Verifiable Quantum Advantage via Optimized DQI Circuits
Tanuj Khattar, Noah Shutty, Craig Gidney +5
Decoded Quantum Interferometry (DQI) provides a framework for superpolynomial quantum speedups by reducing certain optimization problems to reversible decoding tasks. We apply DQI…
Virtual Distillation for Quantum Error Mitigation
William J. Huggins, Sam McArdle, Thomas E. O'Brien +6
Contemporary quantum computers have relatively high levels of noise, making it difficult to use them to perform useful calculations, even with a large number of qubits. Quantum err…
Thermalization and Criticality on an Analog-Digital Quantum Simulator
Trond I. Andersen, Nikita Astrakhantsev, Amir H. Karamlou +224
Understanding how interacting particles approach thermal equilibrium is a major challenge of quantum simulators. Unlocking the full potential of such systems toward this goal requi…
Observation of disorder-free localization using a (2+1)D lattice gauge theory on a quantum processor
Gaurav Gyawali, Shashwat Kumar, Yuri D. Lensky +219
Disorder-induced phenomena in quantum many-body systems pose significant challenges for analytical methods and numerical simulations at relevant time and system scales. To reduce t…
Non-Abelian braiding of graph vertices in a superconducting processor
Trond I. Andersen, Yuri D. Lensky, Kostyantyn Kechedzhi +166
Indistinguishability of particles is a fundamental principle of quantum mechanics. For all elementary and quasiparticles observed to date - including fermions, bosons, and Abelian…
What is the Computational Value of Finite Range Tunneling?
Vasil S. Denchev, Sergio Boixo, Sergei V. Isakov +5
Quantum annealing (QA) has been proposed as a quantum enhanced optimization heuristic exploiting tunneling. Here, we demonstrate how finite range tunneling can provide considerable…
Exponentially More Precise Quantum Simulation of Fermions in the Configuration Interaction Representation
Ryan Babbush, Dominic W. Berry, Yuval R. Sanders +5
We present a quantum algorithm for the simulation of molecular systems that is asymptotically more efficient than all previous algorithms in the literature in terms of the main pro…
Quantum-Classical Separation in Bounded-Resource Tasks Arising from Measurement Contextuality
Shashwat Kumar, Eliott Rosenberg, Alejandro Grajales Dau +280
The prevailing view is that quantum phenomena can be harnessed to tackle certain problems beyond the reach of classical approaches. Quantifying this capability as a quantum-classic…
Quantum Error Mitigation
Zhenyu Cai, Ryan Babbush, Simon C. Benjamin +5
For quantum computers to successfully solve real-world problems, it is necessary to tackle the challenge of noise: the errors which occur in elementary physical components due to u…
What the foundations of quantum computer science teach us about chemistry
Jarrod R. McClean, Nicholas C. Rubin, Joonho Lee +5
With the rapid development of quantum technology, one of the leading applications is the simulation of chemistry. Interestingly, even before full scale quantum computers are availa…
Fast quantum simulation of electronic structure by spectrum amplification
Guang Hao Low, Robbie King, Dominic W. Berry +6
The most advanced techniques using fault-tolerant quantum computers to estimate the ground-state energy of a chemical Hamiltonian involve compression of the Coulomb operator throug…
Optimal scaling quantum linear systems solver via discrete adiabatic theorem
Pedro C. S. Costa, Dong An, Yuval R. Sanders +3
Recently, several approaches to solving linear systems on a quantum computer have been formulated in terms of the quantum adiabatic theorem for a continuously varying Hamiltonian.…
Quantum Simulation of Helium Hydride in a Solid-State Spin Register
Ya Wang, Florian Dolde, Jacob Biamonte +8
\emph{Ab initio} computation of molecular properties is one of the most promising applications of quantum computing. While this problem is widely believed to be intractable for cla…
Hartree-Fock on a superconducting qubit quantum computer
Frank Arute, Kunal Arya, Ryan Babbush +79
As the search continues for useful applications of noisy intermediate scale quantum devices, variational simulations of fermionic systems remain one of the most promising direction…
Optimization by Decoded Quantum Interferometry
Stephen P. Jordan, Noah Shutty, Mary Wootters +6
Achieving superpolynomial speedups for optimization has long been a central goal for quantum algorithms. Here we introduce Decoded Quantum Interferometry (DQI), a quantum algorithm…
Observation of separated dynamics of charge and spin in the Fermi-Hubbard model
Frank Arute, Kunal Arya, Ryan Babbush +96
Strongly correlated quantum systems give rise to many exotic physical phenomena, including high-temperature superconductivity. Simulating these systems on quantum computers may avo…
Strategies for quantum computing molecular energies using the unitary coupled cluster ansatz
Jonathan Romero, Ryan Babbush, Jarrod R. McClean +3
The variational quantum eigensolver (VQE) algorithm combines the ability of quantum computers to efficiently compute expectation values with a classical optimization routine in ord…
Quantum Simulation of the Sachdev-Ye-Kitaev Model by Asymmetric Qubitization
Ryan Babbush, Dominic Berry, Hartmut Neven
We show that one can quantum simulate the dynamics of a Sachdev-Ye-Kitaev model with Majorana modes for time to precision with gate complexity $O(N^{7/2} t + N^{5/2} t…
A simplified version of the quantum OTOC problem
Robbie King, Robin Kothari, Ryan Babbush +4
This note presents a simplified version of the OTOC problem that was recently experimentally implemented by Google Quantum AI and collaborators. We present a formulation of…
Fault-tolerant quantum simulation of materials using Bloch orbitals
Nicholas C. Rubin, Dominic W. Berry, Fionn D. Malone +8
The simulation of chemistry is among the most promising applications of quantum computing. However, most prior work exploring algorithms for block-encoding, time-evolving, and samp…
Suppressing quantum errors by scaling a surface code logical qubit
Rajeev Acharya, Igor Aleiner, Richard Allen +154
Practical quantum computing will require error rates that are well below what is achievable with physical qubits. Quantum error correction offers a path to algorithmically-relevant…
Fault-Tolerant Quantum Simulations of Chemistry in First Quantization
Yuan Su, Dominic W. Berry, Nathan Wiebe +2
Quantum simulations of chemistry in first quantization offer important advantages over approaches in second quantization including faster convergence to the continuum limit and the…
Low depth mechanisms for quantum optimization
Jarrod R. McClean, Matthew P. Harrigan, Masoud Mohseni +6
One of the major application areas of interest for both near-term and fault-tolerant quantum computers is the optimization of classical objective functions. In this work, we develo…
Analyzing Prospects for Quantum Advantage in Topological Data Analysis
Dominic W. Berry, Yuan Su, Casper Gyurik +7
Lloyd et al. were first to demonstrate the promise of quantum algorithms for computing Betti numbers, a way to characterize topological features of data sets. Here, we propose, ana…
Compressing Many-Body Fermion Operators Under Unitary Constraints
Nicholas C. Rubin, Joonho Lee, Ryan Babbush
The most efficient known quantum circuits for preparing unitary coupled cluster states and applying Trotter steps of the arbitrary basis electronic structure Hamiltonian involve in…
Resource Efficient Gadgets for Compiling Adiabatic Quantum Optimization Problems
Ryan Babbush, Bryan O'Gorman, Alán Aspuru-Guzik
We develop a resource efficient method by which the ground-state of an arbitrary k-local, optimization Hamiltonian can be encoded as the ground-state of a (k-1)-local optimization…
Construction of non-convex polynomial loss functions for training a binary classifier with quantum annealing
Ryan Babbush, Vasil Denchev, Nan Ding +2
Quantum annealing is a heuristic quantum algorithm which exploits quantum resources to minimize an objective function embedded as the energy levels of a programmable physical syste…
Quantum computation of molecular structure using data from challenging-to-classically-simulate nuclear magnetic resonance experiments
Thomas E. O'Brien, Lev B. Ioffe, Yuan Su +4
We propose a quantum algorithm for inferring the molecular nuclear spin Hamiltonian from time-resolved measurements of spin-spin correlators, which can be obtained via nuclear magn…
Increasing the representation accuracy of quantum simulations of chemistry without extra quantum resources
Tyler Takeshita, Nicholas C. Rubin, Zhang Jiang +3
Proposals for near-term experiments in quantum chemistry on quantum computers leverage the ability to target a subset of degrees of freedom containing the essential quantum behavio…
Constructive interference at the edge of quantum ergodic dynamics
Dmitry A. Abanin, Rajeev Acharya, Laleh Aghababaie-Beni +262
Quantum observables in the form of few-point correlators are the key to characterizing the dynamics of quantum many-body systems. In dynamics with fast entanglement generation, qua…
Discontinuous Galerkin discretization for quantum simulation of chemistry
Jarrod R. McClean, Fabian M. Faulstich, Qinyi Zhu +5
Methods for electronic structure based on Gaussian and molecular orbital discretizations offer a well established, compact representation that forms much of the foundation of corre…
Low Depth Quantum Simulation of Electronic Structure
Ryan Babbush, Nathan Wiebe, Jarrod McClean +3
Quantum simulation of the electronic structure problem is one of the most researched applications of quantum computing. The majority of quantum algorithms for this problem encode t…
Quantum chemistry calculations on a trapped-ion quantum simulator
Cornelius Hempel, Christine Maier, Jonathan Romero +10
Quantum-classical hybrid algorithms are emerging as promising candidates for near-term practical applications of quantum information processors in a wide variety of fields ranging…
Demonstrating dynamic surface codes
Alec Eickbusch, Matt McEwen, Volodymyr Sivak +204
A remarkable characteristic of quantum computing is the potential for reliable computation despite faulty qubits. This can be achieved through quantum error correction, which is ty…
Hilbert space signatures of non-ergodic glassy dynamics
Aleksey Lunkin, Nicole S. Ticea, Shashwat Kumar +292
Disorder in quantum many-body systems can drive transitions between ergodic and non-ergodic phases, yet the nature--and even the existence--of these transitions remains intensely d…
Exponential quantum speedup in simulating coupled classical oscillators
Ryan Babbush, Dominic W. Berry, Robin Kothari +2
We present a quantum algorithm for simulating the classical dynamics of coupled oscillators (e.g., masses coupled by springs). Our approach leverages a mapping between…
Expressing and Analyzing Quantum Algorithms with Qualtran
Matthew P. Harrigan, Tanuj Khattar, Charles Yuan +5
Quantum computing's transition from theory to reality has spurred the need for novel software tools to manage the increasing complexity, sophistication, toil, and fallibility of qu…
Adiabatic Quantum Simulation of Quantum Chemistry
Ryan Babbush, Peter J. Love, Alán Aspuru-Guzik
We show how to apply the quantum adiabatic algorithm directly to the quantum computation of molecular properties. We describe a procedure to map electronic structure Hamiltonians t…
Encoding Electronic Spectra in Quantum Circuits with Linear T Complexity
Ryan Babbush, Craig Gidney, Dominic W. Berry +5
We construct quantum circuits which exactly encode the spectra of correlated electron models up to errors from rotation synthesis. By invoking these circuits as oracles within the…
Hamiltonian gadgets with reduced resource requirements
Yudong Cao, Ryan Babbush, Jacob Biamonte +1
Application of the adiabatic model of quantum computation requires efficient encoding of the solution to computational problems into the lowest eigenstate of a Hamiltonian that sup…
Observation of disorder-induced superfluidity
Nicole Ticea, Elias Portoles, Eliott Rosenberg +298
The emergence of states with long-range correlations in a disordered landscape is rare, as disorder typically suppresses the particle mobility required for long-range coherence. Bu…
Nearly Optimal Quantum Algorithm for Estimating Multiple Expectation Values
William J. Huggins, Kianna Wan, Jarrod McClean +3
Many quantum algorithms involve the evaluation of expectation values. Optimal strategies for estimating a single expectation value are known, requiring a number of state preparatio…
Efficient and Noise Resilient Measurements for Quantum Chemistry on Near-Term Quantum Computers
William J. Huggins, Jarrod McClean, Nicholas Rubin +4
Variational algorithms are a promising paradigm for utilizing near-term quantum devices for modeling electronic states of molecular systems. However, previous bounds on the measure…
Improved Techniques for Preparing Eigenstates of Fermionic Hamiltonians
Dominic W. Berry, Mária Kieferová, Artur Scherer +5
Modeling low energy eigenstates of fermionic systems can provide insight into chemical reactions and material properties and is one of the most anticipated applications of quantum…
Quantum Simulation of Electronic Structure with Linear Depth and Connectivity
Ian D. Kivlichan, Jarrod McClean, Nathan Wiebe +4
As physical implementations of quantum architectures emerge, it is increasingly important to consider the cost of algorithms for practical connectivities between qubits. We show th…
A Denser Planar Surface Code
Guang Hao Low, William J. Huggins, Dominic W. Berry +4
We present a quantum code implementable on a regular D hex grid with an estimated encoding rate up to of that of a rotated surface code patch using circuit-level noi…
Bayesian Network Structure Learning Using Quantum Annealing
Bryan O'Gorman, Alejandro Perdomo-Ortiz, Ryan Babbush +2
We introduce a method for the problem of learning the structure of a Bayesian network using the quantum adiabatic algorithm. We do so by introducing an efficient reformulation of a…
Response to "Exponential challenges in unbiasing quantum Monte Carlo algorithms with quantum computers"
Joonho Lee, David R. Reichman, Ryan Babbush +4
A recent preprint by Mazzola and Carleo numerically investigates exponential challenges that can arise for the QC-QMC algorithm introduced in our work, "Unbiasing fermionic quantum…
Quantum advantage in learning from experiments
Hsin-Yuan Huang, Michael Broughton, Jordan Cotler +8
Quantum technology has the potential to revolutionize how we acquire and process experimental data to learn about the physical world. An experimental setup that transduces data fro…
Nearly Optimal Measurement Scheduling for Partial Tomography of Quantum States
Xavier Bonet-Monroig, Ryan Babbush, Thomas E. O'Brien
Many applications of quantum simulation require to prepare and then characterize quantum states by performing an efficient partial tomography to estimate observables corresponding…
Measurement-induced entanglement and teleportation on a noisy quantum processor
Jesse C. Hoke, Matteo Ippoliti, Eliott Rosenberg +160
Measurement has a special role in quantum theory: by collapsing the wavefunction it can enable phenomena such as teleportation and thereby alter the "arrow of time" that constrains…
Supplementary information for "Quantum supremacy using a programmable superconducting processor"
Frank Arute, Kunal Arya, Ryan Babbush +74
This is an updated version of supplementary information to accompany "Quantum supremacy using a programmable superconducting processor", an article published in the October 24, 201…
The Fermionic Quantum Emulator
Nicholas C. Rubin, Klaas Gunst, Alec White +5
The fermionic quantum emulator (FQE) is a collection of protocols for emulating quantum dynamics of fermions efficiently taking advantage of common symmetries present in chemical,…
Noise-resilient Edge Modes on a Chain of Superconducting Qubits
Xiao Mi, Michael Sonner, Murphy Yuezhen Niu +125
Inherent symmetry of a quantum system may protect its otherwise fragile states. Leveraging such protection requires testing its robustness against uncontrolled environmental intera…
Quantum Approximate Optimization of Non-Planar Graph Problems on a Planar Superconducting Processor
Matthew P. Harrigan, Kevin J. Sung, Matthew Neeley +83
We demonstrate the application of the Google Sycamore superconducting qubit quantum processor to combinatorial optimization problems with the quantum approximate optimization algor…
Bounding the costs of quantum simulation of many-body physics in real space
Ian D. Kivlichan, Nathan Wiebe, Ryan Babbush +1
We present a quantum algorithm for simulating the dynamics of a first-quantized Hamiltonian in real space based on the truncated Taylor series algorithm. We avoid the possibility o…
The Grand Challenge of Quantum Applications
Ryan Babbush, Robbie King, Sergio Boixo +6
This perspective outlines promising pathways and critical obstacles on the road to developing useful quantum computing applications, drawing on insights from the Google Quantum AI…
Construction of Energy Functions for Lattice Heteropolymer Models: A Case Study in Constraint Satisfaction Programming and Adiabatic Quantum Optimization
Ryan Babbush, Alejandro Perdomo-Ortiz, Bryan O'Gorman +2
Optimization problems associated with the interaction of linked particles are at the heart of polymer science, protein folding and other important problems in the physical sciences…
Error mitigation via verified phase estimation
Thomas E. O'Brien, Stefano Polla, Nicholas C. Rubin +5
The accumulation of noise in quantum computers is the dominant issue stymieing the push of quantum algorithms beyond their classical counterparts. We do not expect to be able to af…
Visualizing Dynamics of Charges and Strings in (2+1)D Lattice Gauge Theories
Tyler A. Cochran, Bernhard Jobst, Eliott Rosenberg +189
Lattice gauge theories (LGTs) can be employed to understand a wide range of phenomena, from elementary particle scattering in high-energy physics to effective descriptions of many-…
The discrete adiabatic quantum linear system solver has lower constant factors than the randomized adiabatic solver
Pedro C. S. Costa, Dong An, Ryan Babbush +1
The solution of linear systems of equations is the basis of many other quantum algorithms, and recent results provided an algorithm with optimal scaling in both the condition numbe…
OpenFermion: The Electronic Structure Package for Quantum Computers
Jarrod R. McClean, Kevin J. Sung, Ian D. Kivlichan +32
Quantum simulation of chemistry and materials is predicted to be an important application for both near-term and fault-tolerant quantum devices. However, at present, developing and…
Shadow Hamiltonian Simulation
Rolando D. Somma, Robbie King, Robin Kothari +2
Simulating quantum dynamics is one of the most important applications of quantum computers. Traditional approaches for quantum simulation involve preparing the full evolved state o…
Quantum simulation of electronic structure via quantum fast multipole method
Dominic W. Berry, Kianna Wan, Andrew D. Baczewski +3
Here we describe an approach for simulating electronic structure on quantum computers with significantly lower asymptotic complexity than prior work. The approach uses a real-space…
Quantum computation of stopping power for inertial fusion target design
Nicholas C. Rubin, Dominic W. Berry, Alina Kononov +7
Stopping power is the rate at which a material absorbs the kinetic energy of a charged particle passing through it -- one of many properties needed over a wide range of thermodynam…
Observation of Time-Crystalline Eigenstate Order on a Quantum Processor
Xiao Mi, Matteo Ippoliti, Chris Quintana +102
Quantum many-body systems display rich phase structure in their low-temperature equilibrium states. However, much of nature is not in thermal equilibrium. Remarkably, it was recent…
TensorFlow Quantum: A Software Framework for Quantum Machine Learning
Michael Broughton, Guillaume Verdon, Trevor McCourt +26
We introduce TensorFlow Quantum (TFQ), an open source library for the rapid prototyping of hybrid quantum-classical models for classical or quantum data. This framework offers high…
Postponing the orthogonality catastrophe: efficient state preparation for electronic structure simulations on quantum devices
Norm M. Tubman, Carlos Mejuto-Zaera, Jeffrey M. Epstein +8
Despite significant work on resource estimation for quantum simulation of electronic systems, the challenge of preparing states with sufficient ground state support has so far been…
Efficient quantum computation of molecular forces and other energy gradients
Thomas E. O'Brien, Michael Streif, Nicholas C. Rubin +12
While most work on the quantum simulation of chemistry has focused on computing energy surfaces, a similarly important application requiring subtly different algorithms is the comp…
Formation of robust bound states of interacting microwave photons
Alexis Morvan, Trond I. Andersen, Xiao Mi +147
Systems of correlated particles appear in many fields of science and represent some of the most intractable puzzles in nature. The computational challenge in these systems arises w…
Exploiting locality in quantum computation for quantum chemistry
Jarrod R. McClean, Ryan Babbush, Peter J. Love +1
Accurate prediction of chemical and material properties from first principles quantum chemistry is a challenging task on traditional computers. Recent developments in quantum compu…
Dynamics of magnetization at infinite temperature in a Heisenberg spin chain
Eliott Rosenberg, Trond Andersen, Rhine Samajdar +178
Understanding universal aspects of quantum dynamics is an unresolved problem in statistical mechanics. In particular, the spin dynamics of the 1D Heisenberg model were conjectured…
Majorana loop stabilizer codes for error correction of fermionic quantum simulations
Zhang Jiang, Jarrod McClean, Ryan Babbush +1
Fermion-to-qubit mappings that preserve geometric locality are especially useful for simulating lattice fermion models (e.g., the Hubbard model) on a quantum computer. They avoid t…
Chemical Basis of Trotter-Suzuki Errors in Quantum Chemistry Simulation
Ryan Babbush, Jarrod McClean, Dave Wecker +2
Although the simulation of quantum chemistry is one of the most anticipated applications of quantum computing, the scaling of known upper bounds on the complexity of these algorith…
The FLuid Allocation of Surface code Qubits (FLASQ) cost model for early fault-tolerant quantum algorithms
William J. Huggins, Tanuj Khattar, Amanda Xu +6
Holistic resource estimates are essential for guiding the development of fault-tolerant quantum algorithms and the computers they will run on. This is particularly true when we foc…
Information Scrambling in Computationally Complex Quantum Circuits
Xiao Mi, Pedram Roushan, Chris Quintana +90
Interaction in quantum systems can spread initially localized quantum information into the many degrees of freedom of the entire system. Understanding this process, known as quantu…
Quartic quantum speedups for planted inference
Alexander Schmidhuber, Ryan O'Donnell, Robin Kothari +1
We describe a quantum algorithm for the Planted Noisy XOR problem (also known as sparse Learning Parity with Noise) that achieves a nearly quartic (th power) speedup over the…
Compilation of Fault-Tolerant Quantum Heuristics for Combinatorial Optimization
Yuval R. Sanders, Dominic W. Berry, Pedro C. S. Costa +5
Here we explore which heuristic quantum algorithms for combinatorial optimization might be most practical to try out on a small fault-tolerant quantum computer. We compile circuits…
Focus beyond quadratic speedups for error-corrected quantum advantage
Ryan Babbush, Jarrod McClean, Michael Newman +3
In this perspective, we discuss conditions under which it would be possible for a modest fault-tolerant quantum computer to realize a runtime advantage by executing a quantum algor…
Quantum Simulation of Chemistry with Sublinear Scaling in Basis Size
Ryan Babbush, Dominic W. Berry, Jarrod R. McClean +1
We present a quantum algorithm for simulating quantum chemistry with gate complexity where is the number of electrons and is the number of pl…
Triply efficient shadow tomography
Robbie King, David Gosset, Robin Kothari +1
Given copies of a quantum state , a shadow tomography protocol aims to learn all expectation values from a fixed set of observables, to within a given precision . We say th…
Precision quantum simulation of magnon spectra and interactions
Trond I. Andersen, Nikita Astrakhantsev, Jeronimo Martinez +329
Quantum simulation promises to advance materials discovery by accurately simulating complex states of matter, their microscopic excitations, and macroscopic response functions. The…