Quantum Brain

Papers

Live trends in quantum computing research, updated daily from arXiv.

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28,891

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13,849 papers in 12 months (-10% vs prior quarter)

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Papers by research theme (12 months). Hover for details.

Qubit Platforms

Hardware platform mentions in abstractsPhotonic leads

6,349 papers found

Considerations for evaluating thermodynamic properties with hybrid quantum-classical computing work flows

Spencer T. Stober, Stuart M. Harwood, Dimitar Trenev +3 more·Mar 4, 2020

Quantum chemistry applications on quantum computers currently rely heavily on the variational quantum eigensolver (VQE) algorithm. This hybrid quantum-classical algorithm aims at finding ground state solutions of molecular systems based on the variat...

Physics

Hierarchies of localizable entanglement due to spatial distribution of local noise

R. Banerjee, A. Pal, Aditi Sen(De)·Mar 4, 2020

Complete characterization of a noisy multipartite quantum state in terms of entanglement requires full knowledge of how the entanglement content in the state is affected by the spatial distribution of noise in the state. Specifically, we find that if...

PhysicsComputer Science

Precise Quantum Simulations with Optical Lattices

Xingze Qiu, Xiaopeng Li·Mar 3, 2020

We present an efficient approach to precisely simulate tight binding models with optical lattices, based on programmable digital-micromirror-device (DMD) techniques. Our approach consists of a subroutine of Wegner-flow enabled precise extraction of a...

Computer SciencePhysics

Calculating nonadiabatic couplings and Berry's phase by variational quantum eigensolvers

Shiro Tamiya, Sho Koh, Yuya O. Nakagawa·Mar 3, 2020

Investigating systems in quantum chemistry and quantum many-body physics with the variational quantum eigensolver (VQE) is one of the most promising applications of forthcoming near-term quantum computers. The VQE is a variational algorithm for findi...

Physics

Improved Simulation of Quantum Circuits by Fewer Gaussian Eliminations

L. Kocia, M. Sarovar·Mar 2, 2020

We show that the cost of strong simulation of quantum circuits using $t$ $T$ gate magic states exhibits non-trivial reductions on its upper bound for $t=1$, $t=2$, $t=3$, and $t=6$ with odd-prime-qudits. This agrees with previous numerical bounds fou...

Physics

Digital quantum simulation of molecular dynamics and control

Alicia B. Magann, Matthew D. Grace, H. Rabitz +1 more·Feb 28, 2020

Optimally-shaped electromagnetic fields have the capacity to coherently control the dynamics of quantum systems, and thus offer a promising means for controlling molecular transformations relevant to chemical, biological, and materials applications. ...

Computer SciencePhysics

Finding the ground state of spin Hamiltonians with reinforcement learning

K. Mills, Pooya Ronagh, Isaac Tamblyn·Feb 28, 2020

Reinforcement learning (RL) has become a proven method for optimizing a procedure for which success has been defined, but the specific actions needed to achieve it have not. Using a method we call ‘controlled online optimization learning’ (COOL), we ...

Computer SciencePhysicsEngineering

Chemistry on Quantum Computers with Virtual Quantum Subspace Expansion.

M. Urbánek, Daan Camps, Roel Van Beeumen +1 more·Feb 28, 2020

Simulating chemical systems on quantum computers has been limited to a few electrons in a minimal basis. We demonstrate experimentally that the virtual quantum subspace expansion (Takeshita, T.; Phys. Rev. X 2020, 10, 011004, 10.1103/PhysRevX.10.0110...

MedicinePhysics

Predicting excited states from ground state wavefunction by supervised quantum machine learning

H. Kawai, Yuya O. Nakagawa·Feb 28, 2020

Excited states of molecules lie in the heart of photochemistry and chemical reactions. The recent development in quantum computational chemistry leads to inventions of a variety of algorithms that calculate the excited states of molecules on near-ter...

PhysicsComputer Science

Approximating the quantum approximate optimization algorithm with digital-analog interactions

David Headley, T. Müller, Ana Martin +3 more·Feb 27, 2020

The quantum approximate optimisation algorithm was proposed as a heuristic method for solving combinatorial optimisation problems on near-term quantum computers and may be among the first algorithms to perform useful computations in the post-supremac...

Physics

Efficient phase-factor evaluation in quantum signal processing

Yulong Dong, X. Meng, K. B. Whaley +1 more·Feb 26, 2020

Quantum signal processing (QSP) is a powerful quantum algorithm to exactly implement matrix polynomials on quantum computers. Asymptotic analysis of quantum algorithms based on QSP has shown that asymptotically optimal results can in principle be obt...

Computer SciencePhysicsMathematics

Quantum Algorithms for Simulating the Lattice Schwinger Model

Alexander F. Shaw, P. Lougovski, Jesse R. Stryker +1 more·Feb 25, 2020

The Schwinger model (quantum electrodynamics in 1+1 dimensions) is a testbed for the study of quantum gauge field theories. We give scalable, explicit digital quantum algorithms to simulate the lattice Schwinger model in both NISQ and fault-tolerant ...

Computer SciencePhysics

Codar: A Contextual Duration-Aware Qubit Mapping for Various NISQ Devices

Haowei Deng, Yu Zhang, Quanxi Li·Feb 24, 2020

Quantum computing devices in the NISQ era share common features and challenges like limited connectivity between qubits. Since two-qubit gates are allowed on limited qubit pairs, quantum compilers must transform original quantum programs to fit the h...

Computer SciencePhysics

Alibaba Cloud Quantum Development Platform: Surface Code Simulations with Crosstalk

Cupjin Huang, Xiaotong Ni, Fang Zhang +11 more·Feb 20, 2020

We report, in a sequence of notes, our work on the Alibaba Cloud Quantum Development Platform (AC-QDP). AC-QDP provides a set of tools for aiding the development of both quantum computing algorithms and quantum processors, and is powered by a large-s...

PhysicsComputer Science

What Limits the Simulation of Quantum Computers?

Yiqing Zhou, E. Stoudenmire, X. Waintal·Feb 18, 2020

It is imperative that useful quantum computers be very difficult to simulate classically; otherwise classical computers could be used for the applications envisioned for the quantum ones. Perfect quantum computers are unarguably exponentially difficu...

PhysicsComputer Science

Scaling up electronic structure calculations on quantum computers: The frozen natural orbital based method of increments.

P. Verma, Lee M J Huntington, Marc P. Coons +3 more·Feb 18, 2020

The method of increments and frozen natural orbital (MI-FNO) framework is introduced to help expedite the application of noisy, intermediate-scale quantum (NISQ) devices for quantum chemistry simulations. The MI-FNO framework provides a systematic re...

MedicinePhysics

Leakage detection for a transmon-based surface code

B. Varbanov, F. Battistel, B. Tarasinski +4 more·Feb 17, 2020

Leakage outside of the qubit computational subspace, present in many leading experimental platforms, constitutes a threatening error for quantum error correction (QEC) for qubits. We develop a leakage-detection scheme via Hidden Markov models (HMMs) ...

PhysicsComputer Science

Quantifying Quantum Speedups: Improved Classical Simulation From Tighter Magic Monotones

James Robert Seddon, Bartosz Regula, Hakop Pashayan +2 more·Feb 14, 2020

Consumption of magic states promotes the stabilizer model of computation to universal quantum computation. Here, we propose three different classical algorithms for simulating such universal quantum circuits. Our first simulator introduces a new clas...

PhysicsComputer Science

Classical simulation of noncontextual Pauli Hamiltonians

William M. Kirby, P. Love·Feb 13, 2020

Noncontextual Pauli Hamiltonians decompose into sets of Pauli terms to which joint values may be assigned without contradiction. We construct a quasi-quantized model for noncontextual Pauli Hamiltonians. Using this model, we give an algorithm to clas...

Physics

Identification of Symmetry-Protected Topological States on Noisy Quantum Computers.

Daniel Azses, R. Haenel, Y. Naveh +3 more·Feb 11, 2020

Identifying topological properties is a major challenge because, by definition, topological states do not have a local order parameter. While a generic solution to this challenge is not available yet, a broad class of topological states, namely, symm...

PhysicsMedicineComputer Science
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