Quantum Brain

Papers

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

Total Papers

28,494

This Month

224

Today

0

Research Volume

13,581 papers in 12 months (-18% vs prior quarter)

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

Qubit Platforms

Hardware platform mentions in abstractsPhotonic leads

5,331 papers found

Implementations of two-photon four-qubit Toffoli and Fredkin gates assisted by nitrogen-vacancy centers

Hai‐Rui Wei, Pei Zhu·Oct 24, 2016

It is desirable to implement an efficient quantum information process demanding fewer quantum resources. We designed two compact quantum circuits for determinately implementing four-qubit Toffoli and Fredkin gates on single-photon systems in both the...

MedicineComputer SciencePhysics

Limits on the storage of quantum information in a volume of space

S. Flammia, Jeongwan Haah, M. Kastoryano +1 more·Oct 19, 2016

We study the fundamental limits on the reliable storage of quantum information in lattices of qubits by deriving tradeoff bounds for approximate quantum error correcting codes. We introduce a notion of local approximate correctability and code distan...

Computer ScienceMathematicsPhysics

Fidelity as a figure of merit in quantum error correction

J. Almlof, G. Bjork·Oct 12, 2016

We discuss the fidelity as a figure of merit in quantum error correction schemes. We show that when identifiable but uncorrectable errors occur as a result of the action of the channel, a common strategy that improves the fidelity actually decreases ...

Physics

Noise Threshold of Quantum Supremacy

K. Fujii·Oct 12, 2016

Demonstrating quantum supremacy, a complexity-guaranteed quantum advantage against over the best classical algorithms by using less universal quantum devices, is an important near-term milestone for quantum information processing. Here we develop a t...

PhysicsMathematics

Hybrid quantum gate and entanglement between a "stationary" photonic qubit and a flying optical state via a giant cross Kerr nonlinear effect

K. Xia, J. Twamley·Oct 11, 2016

Quantum information processing with hybrid protocols making use of discrete- and continuous-variable currently attracts of great interest because of its promising applications in scalable quantum computer and distant quantum network. By inducing a gi...

Physics

Entanglement detection on an NMR quantum-information processor using random local measurements

Amandeep Singh, Arvind, K. Dorai·Oct 8, 2016

Random local measurements have recently been proposed to construct entanglement witnesses and thereby detect the presence of bipartite entanglement. We experimentally demonstrate the efficacy of one such scheme on a two-qubit NMR quantum information ...

Physics

Quantum information processing with superconducting circuits: a review

G. Wendin·Oct 7, 2016

During the last ten years, superconducting circuits have passed from being interesting physical devices to becoming contenders for near-future useful and scalable quantum information processing (QIP). Advanced quantum simulation experiments have been...

MedicinePhysics

Resolving quanta of collective spin excitations in a millimeter-sized ferromagnet

D. Lachance-Quirion, Y. Tabuchi, Seiichiro Ishino +4 more·Oct 4, 2016

Quanta of collective spin excitations are observed in a ferromagnet by measurements of a superconducting quantum bit. Combining different physical systems in hybrid quantum circuits opens up novel possibilities for quantum technologies. In quantum ma...

MedicinePhysics

Generating entangled quantum microwaves in a Josephson-photonics device

S. Dambach, B. Kubala, J. Ankerhold·Sep 28, 2016

When connecting a voltage-biased Josephson junction in series to several microwave cavities, a Cooper-pair current across the junction gives rise to a continuous emission of strongly correlated photons into the cavity modes. Tuning the bias voltage t...

Physics

Distinguishing quantum states using Clifford orbits

R. Kueng, Huangjun Zhu, D. Gross·Sep 27, 2016

It is a fundamental property of quantum mechanics that information is lost as a result of performing measurements. Indeed, with every quantum measurement one can associate a number -- its POVM norm constant -- that quantifies how much the distinguish...

MathematicsPhysics

Fault-tolerant interface between quantum memories and quantum processors

Hendrik Poulsen Nautrup, N. Friis, H. Briegel·Sep 26, 2016

Topological error correction codes are promising candidates to protect quantum computations from the deteriorating effects of noise. While some codes provide high noise thresholds suitable for robust quantum memories, others allow straightforward gat...

MedicineComputer SciencePhysicsMathematics

The Clifford group fails gracefully to be a unitary 4-design

Huangjun Zhu, R. Kueng, M. Grassl +1 more·Sep 26, 2016

A unitary t-design is a set of unitaries that is "evenly distributed" in the sense that the average of any t-th order polynomial over the design equals the average over the entire unitary group. In various fields -- e.g. quantum information theory --...

PhysicsMathematics

Demonstrating non-Abelian braiding of surface code defects in a five qubit experiment

James R. Wootton·Sep 25, 2016

Currently, the mainstream approach to quantum computing is through surface codes. One way to store and manipulate quantum information with these to create defects in the codes which can be moved and used as if they were particles. Specifically, they ...

Physics

From Digital computers to quantum computers based on biological paradigms and progress in particle physics

P. Borza, L. Pau·Sep 24, 2016

While several paths have emerged in microelectronics and computing as follow-ons to Turing architectures, and have been implemented using essentially silicon circuits, very little beyond Moore research has considered: (1) first biological processes i...

Computer Science

Measurement based quantum communication with resource states generated by entanglement purification

Julius Wallnofer, W. Dur·Sep 19, 2016

We investigate measurement-based quantum communication with noisy resource states that are generated by entanglement purification. We consider the transmission of encoded information via noisy quantum channels using a measurement-based implementation...

Physics

Convex separation from convex optimization for large-scale problems

S. Brierley, M. Navascués, T. Vértesi·Sep 16, 2016

We present a scheme, based on Gilbert's algorithm for quadratic minimization [SIAM J. Contrl., vol. 4, pp. 61-80, 1966], to prove separation between a point and an arbitrary convex set $S\subset\mathbb{R}^{n}$ via calls to an oracle able to perform l...

PhysicsMathematics

A Generalization of Bernstein-Vazirani Algorithm to Qudit Systems

R. Krishna, V. Makwana, Ananda Padhmanabhan Suresh·Sep 11, 2016

A quantum algorithm to solve the parity problem is better than its most efficient classical counter- part with a separation that is polynomial in the number of queries. This was shown by E. Bernstein and U. Vazirani and was one of the earliest indica...

PhysicsMathematics

Quantum optical circulator controlled by a single chirally coupled atom

J. Volz, M. Scheucher, A. Hilico +2 more·Sep 8, 2016

A quantum optical circulator A circulator is a passive three- or four-port device that routes signals according to a simple protocol: If the ports are numbered in ascending order, a signal that enters the circulator through port 1, 2, 3, or 4 exits i...

PhysicsMedicineComputer Science

Quantum one-way permutation over the finite field of two elements

A. D. Castro·Sep 5, 2016

In quantum cryptography, a one-way permutation is a bounded unitary operator U:H→H\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage...

PhysicsComputer ScienceMathematics

Wire recycling for quantum circuit optimization

A. Paler, R. Wille, S. Devitt·Sep 3, 2016

Quantum information processing is expressed using quantum bits (qubits) and quantum gates which are arranged in the terms of quantum circuits. Here, each qubit is associated to a quantum circuit wire which is used to conduct the desired operations. M...

Physics
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