Quantum Brain

Papers

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

Total Papers

31,937

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336

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0

Research Volume

15,923 papers in 12 months (-33% vs prior quarter)

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

Qubit Platforms

Hardware platform mentions in abstractsPhotonic leads

31,937 papers found

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

Verifiable fault tolerance in measurement-based quantum computation

K. Fujii, Masahito Hayashi·Oct 17, 2016

Quantum systems, in general, output data that cannot be simulated efficiently by a classical computer, and hence is useful for solving certain mathematical problems and simulating quantum many-body systems. This also implies, unfortunately, that veri...

Physics

Three addressable spin qubits in a molecular single-ion magnet

M. Jenkins, Yan Duan, B. Diosdado +6 more·Oct 13, 2016

We show that several qubits can be integrated in a single magnetic ion, using its internal electronic spin states with energies tuned by a suitably chosen molecular environment. This approach is illustrated with a nearly-isotropic Gd(III) ion entrapp...

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

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

A Low-Overhead Hybrid Approach for Universal Fault-Tolerant Quantum Computation

E. Nikahd, M. S. Zamani, M. Sedighi·Oct 11, 2016

As there is no quantum error correction code with universal set of transversal gates, several approaches have been proposed which, in combination of transversal gates, make universal fault-tolerant quantum computation possible. Magic state distillati...

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

Electronic properties of nano and molecular quantum devices

Oday A Al-Owaedi·Oct 11, 2016

The exploring and understanding the electronic properties of molecules connected to metallic leads is a vital part of nanoscience if molecule is to have a future. This thesis documents a study for various families of organic and organometallic molecu...

PhysicsMaterials Science

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

Environmental noise effects on entanglement fidelity of exchange-coupled semiconductor spin qubits

R. Throckmorton, Edwin Barnes, S. Das Sarma·Oct 6, 2016

We investigate the effect of magnetic field and charge noise on the generation of entanglement between two Heisenberg exchange-coupled electron spins in a double quantum dot. We focus on exchange-driven evolution that would ideally take an initial un...

Physics

Achieving quantum supremacy with sparse and noisy commuting quantum computations

M. Bremner, A. Montanaro, D. Shepherd·Oct 6, 2016

The class of commuting quantum circuits known as IQP (instantaneous quantum polynomial-time) has been shown to be hard to simulate classically, assuming certain complexity-theoretic conjectures. Here we study the power of IQP circuits in the presence...

MathematicsPhysicsComputer Science

Invariance of separability probability over reduced states in 4 × 4 bipartite systems

A. Lovas, Attila Andai·Oct 5, 2016

The geometric separability probability of composite quantum systems has been extensively studied in the recent decades. One of the simplest but strikingly difficult problem is to compute the separability probability of qubit–qubit and rebit–rebit qua...

PhysicsMathematics

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

Nuclear numerical range and quantum error correction codes for non-unitary noise models

Patryk Lipka-Bartosik, K. Życzkowski·Oct 4, 2016

We introduce a notion of nuclear numerical range defined as the set of expectation values of a given operator A among normalized pure states, which belong to the nucleus of an auxiliary operator Z. This notion proves to be applicable to investigate m...

Computer ScienceMathematicsPhysics

A Near-Quadratic Lower Bound for the Size of Quantum Circuits of Constant Treewidth

Mateus de Oliveira Oliveira·Sep 30, 2016

We show that any quantum circuit of treewidth $t$, built from $r$-qubit gates, requires at least $\Omega(\frac{n^{2}}{2^{O(r\cdot t)}\cdot \log^4 n})$ gates to compute the element distinctness function. Our result generalizes a near-quadratic lower b...

MathematicsComputer SciencePhysics

Silicon CMOS architecture for a spin-based quantum computer

M. Veldhorst, M. Veldhorst, H. Eenink +3 more·Sep 30, 2016

Recent advances in quantum error correction codes for fault-tolerant quantum computing and physical realizations of high-fidelity qubits in multiple platforms give promise for the construction of a quantum computer based on millions of interacting qu...

PhysicsMedicine

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

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
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