Quantum Brain

Papers

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

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31,611

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65

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15,670 papers in 12 months (-39% vs prior quarter)

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Qubit Platforms

Hardware platform mentions in abstractsPhotonic leads

31,611 papers found

Translation of Quantum Circuits into Quantum Turing Machines for Deutsch and Deutsch-Jozsa Problems

Giuseppe Corrente·Jan 6, 2021

We want in this article to show the usefulness of Quantum Turing Machine (QTM) in a high-level didactic context as well as in theoretical studies. We use QTM to show its equivalence with quantum circuit model for Deutsch and Deutsch-Jozsa algorithms....

Computer SciencePhysics

Quantum Codes Do Not Fix Qubit Independent Errors

Jesús García López de Lacalle, Luis Miguel Pozo Coronado, A. Oliveira +1 more·Jan 6, 2021

The goal of this work is to analyse the performance of quantum error correction codes in regard to fixing independent errors in several qubits. We say that a quantum code does not fix a quantum computing error if its application does not reduce the v...

Computer SciencePhysics

Modeling and simulating the noisy behavior of near-term quantum computers

K. Georgopoulos, C. Emary, P. Zuliani·Jan 6, 2021

Noise dominates every aspect of near-term quantum computers, rendering it exceedingly difficult to carry out even small computations. In this paper we are concerned with the modelling of noise in Noisy Intermediate-Scale Quantum (NISQ) computers. We ...

Physics

Deep Reinforcement Learning With Quantum-Inspired Experience Replay

Qing Wei, Hailan Ma, Chunlin Chen +1 more·Jan 6, 2021

In this article, a novel training paradigm inspired by quantum computation is proposed for deep reinforcement learning (DRL) with experience replay. In contrast to the traditional experience replay mechanism in DRL, the proposed DRL with quantum-insp...

Computer SciencePhysicsMedicine

In-situ bandaged Josephson junctions for superconducting quantum processors

A. Bilmes, Alexander K Händel, Serhii Volosheniuk +2 more·Jan 5, 2021

Shadow evaporation is commonly used to micro-fabricate the key element of superconducting qubits—the Josephson junction. However, in conventional two-angle deposition circuit topology, unwanted stray Josephson junctions are created which contribute t...

Physics

Quantum Conference Key Agreement with Photon Loss

Phattharaporn Singkanipa, P. Kok·Jan 5, 2021

Conference key agreement (CKA) is an information processing task where more than two parties want to share a common secret key. Here, we present a loss-resilient protocol for CKA, based on redundant encoding and error correction. Our protocol provide...

Physics

Meissner levitation of a permanent magnet within a superconducting radio frequency cavity

N. K. Raut, Jeffery Miller, R. Chiao +1 more·Jan 5, 2021

We report the first experimental demonstration of Meissner-effect levitation of a millimeter-scale neodymium magnet within a cm-scale superconducting aluminum coaxial quarter-wave stub cavity. The coaxial mode's resonance frequency shifts as a functi...

Physics

Single-preparation unsupervised quantum machine learning: concepts and applications

Y. Deville, A. Deville·Jan 5, 2021

The term"machine learning"especially refers to algorithms that derive mappings, i.e. intput/output transforms, by using numerical data that provide information about considered transforms. These transforms appear in many problems, related to classifi...

PhysicsMathematics

Post Quantum Cryptography: Readiness Challenges and the Approaching Storm

Matthew J. Campagna, Brian A. LaMacchia, David E. Ott·Jan 4, 2021

While advances in quantum computing promise new opportunities for scientific advancement (e.g., material science and machine learning), many people are not aware that they also threaten the widely deployed cryptographic algorithms that are the founda...

Computer Science

Quantum codes do not fix isotropic errors

Jesús Lacalle, L. M. P. Coronado, A. Oliveira·Jan 1, 2021

In this work, we prove that quantum error correcting codes do not fix isotropic errors (Theorem 5), even assuming that their correction circuits do not introduce new errors. We say that a quantum code does not fix a quantum computing error if its app...

PhysicsComputer Science

Simulating quantum computations with Tutte polynomials

Ryan L. Mann·Jan 1, 2021

We establish a classical heuristic algorithm for exactly computing quantum probability amplitudes. Our algorithm is based on mapping output probability amplitudes of quantum circuits to evaluations of the Tutte polynomial of graphic matroids. The alg...

Computer SciencePhysicsMathematics

Calculating spin correlations with a quantum computer

J. Brody, G. Guzman·Jan 1, 2021

We calculate spin correlation functions using IBM quantum processors, accessed online. We demonstrate the rotational invariance of the singlet state, interesting properties of the triplet states, and surprising features of a state of three entangled ...

Physics

Radio frequency mixing modules for superconducting qubit room temperature control systems.

Yilun Xu, Gang-Ming Huang, D. Santiago +1 more·Dec 31, 2020

As the number of qubits in nascent quantum processing units increases, the connectorized RF (radio frequency) analog circuits used in first generation experiments become exceedingly complex. The physical size, cost, and electrical failure rate all be...

PhysicsMedicine

Between Shor and Steane: A Unifying Construction for Measuring Error Syndromes.

Shilin Huang, K. Brown·Dec 31, 2020

Fault-tolerant quantum error correction requires the measurement of error syndromes in a way that minimizes correlated errors on the quantum data. Steane and Shor ancilla are two well-known methods for fault-tolerant syndrome extraction. In this Lett...

PhysicsMedicine

QubiC: An Open-Source FPGA-Based Control and Measurement System for Superconducting Quantum Information Processors

Yilun Xu, Gang-Ming Huang, J. Balewski +6 more·Dec 31, 2020

As quantum information processors grow in quantum bit (qubit) count and functionality, the control and measurement system becomes a limiting factor to large-scale extensibility. To tackle this challenge and keep pace with rapidly evolving classical c...

Physics

Berry phase induced entanglement of hole-spin qubits in a microwave cavity

M. Wysoki'nski, M. Plodzie'n, M. Trif·Dec 31, 2020

Hole-spins localized in semiconductor structures, such as quantum dots or defects, serve to the realization of efficient gate-tunable solid-state quantum bits. Here we study two electrically driven spin 3/2 holes coupled to the electromagnetic field ...

Physics

On the Construction of a Post-Quantum Blockchain

Jiahui Chen, Wensheng Gan, Muchuang Hu +1 more·Dec 31, 2020

Consensus and transaction are the main parts in a blockchain system. However, most cryptographic protocols used in these parts of current blockchains are vulnerable to rapid development of quantum computers. Besides, traditional proof of work (PoW) b...

Computer Science

Maximum-Likelihood Quantum State Tomography by Soft-Bayes

Chien-Ming Lin, Y.-M. Hsu, Yen-Huan Li·Dec 31, 2020

Quantum state tomography (QST), the task of estimating an unknown quantum state given measurement outcomes, is essential to building reliable quantum computing devices. Whereas computing the maximum-likelihood (ML) estimate corresponds to solving a f...

Computer ScienceMathematicsPhysics

Trapping Sets of Quantum LDPC Codes

Nithin Raveendran, Bane Vasi'c·Dec 30, 2020

Iterative decoders for finite length quantum low-density parity-check (QLDPC) codes are attractive because their hardware complexity scales only linearly with the number of physical qubits. However, they are impacted by short cycles, detrimental grap...

Computer ScienceMathematicsPhysics

Real-time optimal quantum control of mechanical motion at room temperature

Lorenzo Magrini, Philipp Rosenzweig, Constanze Bach +6 more·Dec 30, 2020

The ability to accurately control the dynamics of physical systems by measurement and feedback is a pillar of modern engineering1. Today, the increasing demand for applied quantum technologies requires adaptation of this level of control to individua...

MedicinePhysics
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