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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Hardware platform mentions in abstractsPhotonic leads

31,611 papers found

Superconducting titanium nitride films grown by directional reactive evaporation

R. Mencia, Yen-Hsiang Lin, V. Manucharyan·Nov 18, 2020

We report a novel method of growing strongly-disordered superconducting titanium nitride (TiN) thin films by reactive electron-beam deposition. The normal state sheet resistance and superconducting critical temperature (Tc) can be tuned by controllin...

PhysicsMaterials Science

Tabu-Driven Quantum Neighborhood Samplers

Charles Moussa, Hao Wang, H. Calandra +2 more·Nov 18, 2020

Combinatorial optimization is an important application targeted by quantum computing. However, near-term hardware constraints make quantum algorithms unlikely to be competitive when compared to high-performing classical heuristics on large practical ...

PhysicsComputer Science

Non-trivial symmetries in quantum landscapes and their resilience to quantum noise

Enrico Fontana, M. Cerezo, A. Arrasmith +2 more·Nov 17, 2020

Very little is known about the cost landscape for parametrized Quantum Circuits (PQCs). Nevertheless, PQCs are employed in Quantum Neural Networks and Variational Quantum Algorithms, which may allow for near-term quantum advantage. Such applications ...

PhysicsComputer ScienceMathematics

Efficient algorithm for generating Pauli coordinates for an arbitrary linear operator

D. Gunlycke, Mark C. Palenik, A. Emmert +1 more·Nov 17, 2020

Several linear algebra routines for quantum computing use a basis of tensor products of identity and Pauli operators to describe linear operators, and obtaining the coordinates for any given linear operator from its matrix representation requires a b...

PhysicsMathematics

Tunable quantum logic gate on photonic qubits with a ladder emitter

Derek S. Wang, David D. Dai, P. Narang·Nov 17, 2020

We describe how a ladder emitter can implement a tunable quantum logic gate on photonic qubits encoded in the frequency basis. The ground-to-first excited state of the ladder emitter interacts with the control photon, and the first-to-second excited ...

Physics

Dispersive measurement of a semiconductor double quantum dot via 3D integration of a high-impedance TiN resonator

Nathan Holman, D. Rosenberg, D. Yost +5 more·Nov 17, 2020

Spins in semiconductor quantum dots are a candidate for cryogenic quantum processors due to their exceptionally long coherence times. One major challenge to scaling quantum dot spin qubits is the dense wiring requirements, making it difficult to envi...

Physics

Fault-Tolerant Qubit from a Constant Number of Components

Kianna Wan, Soonwon Choi, Isaac H. Kim +2 more·Nov 16, 2020

With gate error rates in multiple technologies now below the threshold required for fault-tolerant quantum computation, the major remaining obstacle to useful quantum computation is scaling, a challenge greatly amplified by the huge overhead imposed ...

PhysicsComputer Science

Experimental characterization of quantum processes: A selective and efficient method in arbitrary finite dimensions

Quimey Pears Stefano, I. Perito, Juan Jos'e Miguel Varga +2 more·Nov 16, 2020

The temporal evolution of a quantum system can be characterized by quantum process tomography, a complex task that consumes a number of physical resources scaling exponentially with the number of subsystems. An alternative approach to the full recons...

Computer SciencePhysics

Scrambling ability of quantum neural network architectures

Yadong Wu, Pengfei Zhang, H. Zhai·Nov 16, 2020

In this letter we propose a general principle for how to build up a quantum neural network with high learning efficiency. Our stratagem is based on the equivalence between extracting information from input state to readout qubit and scrambling inform...

Computer SciencePhysics

Secure Vehicle Communications Using Proof-of-Nonce Blockchain

N. Ahn, D. H. Lee·Nov 16, 2020

This paper presents an autonomous driving that achieves physical layer security. Proposed vehicle communication is implemented based on Proof-of-Nonce (PoN) blockchain algorithm. PoN blockchain algorithm is a consensus algorithm that can be implement...

Computer Science

Quantum simulations of molecular systems with intrinsic atomic orbitals

Stefano Barison, D. Galli, M. Motta·Nov 16, 2020

Quantum simulations of quantum chemistry systems on quantum computers often employ minimal basis sets of Gaussian orbitals. In comparison with more realistic basis sets, quantum simulations employing minimal basis sets require fewer qubits and quantu...

Physics

Generating Target Graph Couplings for QAOA from Native Quantum Hardware Couplings

Joel Rajakumar, Jai Moondra, Swati Gupta +1 more·Nov 16, 2020

We present methods for constructing any target coupling graph using limited global controls in an Ising-like quantum spin system. Our approach is motivated by implementing the quantum approximate optimization algorithm (QAOA) on trapped ion quantum h...

Computer SciencePhysicsMathematics

Quantum walk-based portfolio optimisation

N. Slate, Edric Matwiejew, S. Marsh +1 more·Nov 16, 2020

This paper proposes a highly efficient quantum algorithm for portfolio optimisation targeted at near-term noisy intermediate-scale quantum computers. Recent work by Hodson et al. (2019) explored potential application of hybrid quantum-classical algor...

Computer SciencePhysics

Exploiting Quantum Teleportation in Quantum Circuit Mapping

S. Hillmich, Alwin Zulehner, R. Wille·Nov 14, 2020

Quantum computers are constantly growing in their number of qubits, but continue to suffer from restrictions such as the limited pairs of qubits that may interact with each other. Thus far, this problem is addressed by mapping and moving qubits to su...

PhysicsComputer Science

Quantum Period Finding against Symmetric Primitives in Practice

X. Bonnetain, Samuel Jaques·Nov 13, 2020

We present the first complete descriptions of quantum circuits for the offline Simon’s algorithm, and estimate their cost to attack the MAC Chaskey, the block cipher PRINCE and the NIST lightweight finalist AEAD scheme Elephant. These attacks require...

Computer SciencePhysics

Virtual Distillation for Quantum Error Mitigation

W. Huggins, Sam McArdle, T. O’Brien +6 more·Nov 13, 2020

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 error correction is expected to eventually enable fault-tolerant quantum ...

PhysicsComputer Science

Quantum algorithms with local particle-number conservation: Noise effects and error correction

Michael Streif, M. Leib, F. Wudarski +2 more·Nov 13, 2020

Quantum circuits with local particle number conservation (LPNC) restrict the quantum computation to a subspace of the Hilbert space of the qubit register. In a noiseless or fault-tolerant quantum computation, such quantities are preserved. In the pre...

PhysicsComputer Science

Comparative Study of Sampling-Based Simulation Costs of Noisy Quantum Circuits

Shigeo Hakkaku, K. Fujii·Nov 12, 2020

There have been intensive efforts to develop quantum computers, and the number of qubits is now reaching around 50 qubits. In practice, not only the number of qubits but the fidelity of the gates and measurements plays an important role. The noise in...

Computer SciencePhysics

Quantum algorithms for spectral sums

Alessandro Luongo, Changpeng Shao·Nov 12, 2020

We propose new quantum algorithms for estimating spectral sums of positive semi-definite (PSD) matrices. For a matrix A and a function f, the spectral sum is the trace of f(A), equivalently the sum over eigenvalues of A of f applied to each eigenvalu...

Computer ScienceMathematicsPhysics

Theoretical survey of unconventional quantum annealing methods applied to adifficult trial problem.

Zhijie Tang, E. Kapit·Nov 12, 2020

We consider a range of unconventional modifications to Quantum Annealing (QA), applied to an artificial trial problem with continuously tunable difficulty. In this problem, inspired by "transverse field chaos" in larger systems, classical and quantum...

Physics
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