Papers

Pedro C. S. Costa, R. Portugal, F. D. Melo·Mar 6, 2018

Very much as its classical counterpart, quantum cellular automata are expected to be a great tool for simulating complex quantum systems. Here we introduce a partitioned model of quantum cellular automata and show how it can simulate, with the same a...

Anirban Narayan Chowdhury, Yiğit Subaşı, R. Somma·Mar 6, 2018

Quantum algorithms for diverse problems, including search and optimization problems, require the implementation of a reflection operator over a target state. Commonly, such reflections are approximately implemented using phase estimation. Here we use...

L. Gyongyosi·Mar 6, 2018

Gate-model quantum computers provide an experimentally implementable architecture for near-term quantum computations. To design a reduced quantum circuit that can simulate a high-complexity reference quantum circuit, an optimization should be taken o...

C. Baldwin, C. Laumann·Mar 6, 2018

We consider the ability of local quantum dynamics to solve the energy matching problem: given an instance of a classical optimization problem and a low energy state, find another macroscopically distinct low energy state. Energy matching is difficult...

Kishore Thapliyal, A. Pathak·Mar 6, 2018

Kak’s three-stage protocol for quantum key distribution is revisited with special focus on its hitherto unknown strengths and weaknesses. It is shown that this protocol can be used for secure direct quantum communication. Further, the implementabilit...

S. Matsuura, H. Nishimori, W. Vinci +1 more·Mar 5, 2018

Quantum annealing in a real device is necessarily susceptible to errors due to diabatic transitions and thermal noise. Nested quantum annealing correction is a method to suppress errors by using an all-to-all penalty coupling among a set of physical ...

J. Cortese, T. Braje·Mar 5, 2018

This document describes a family of quantum circuits which load classical data into a quantum state. When loading $N$ classical bits, the result quantum state is of order $\log_2(N)$ qubits. Furthermore the gate depth of the data loading circuit is o...

H. Fogedby, A. Imparato·Mar 5, 2018

We consider a minimal model of a quantum rotator composed of a single particle confined in a harmonic potential and driven by two temperature-biased heat reservoirs. In the case the particle potential is rendered asymmetric and rotated an angle, a fi...

M. Ware, G. Ribeill, D. Ristè +3 more·Mar 5, 2018

The realization of quantum computing's promise despite noisy imperfect qubits relies, at its core, on the ability to scale cheaply through error correction and fault-tolerance. While fault-tolerance requires relatively mild assumptions about the natu...

Changpeng Shao·Mar 5, 2018

In this paper, we study quantum algorithms of matrix multiplication from the viewpoint of inputting quantum/classical data to outputting quantum/classical data. The main target is trying to overcome the input and output problem, which are not easy to...

Ming Zhang, Lantian Feng, Zhi-yuan Zhou +7 more·Mar 5, 2018

Multiphoton entanglement plays a critical role in quantum information processing, and greatly improves our fundamental understanding of the quantum world. Despite tremendous efforts in either bulk media or fiber-based devices, nonlinear interactions ...

Yunkai Wang, Shengjun Wu, Wei Wang·Mar 5, 2018

We present quantum algorithms to search for marked vertices in structured databases with low connectivity. Adopting a multi-stage search process, we achieve a success probability close to $100\%$ on Cayley trees with large branching factors. We find ...

Run-Qiu Yang, Yu-Sen An, Chao Niu +2 more·Mar 5, 2018

Based on general and minimal properties of the discrete circuit complexity, we define the complexity in continuous systems in a geometrical way. We first show that the Finsler metric naturally emerges in the geometry of the complexity in continuous s...

Changpeng Shao·Mar 5, 2018

HHL quantum algorithm to solve linear systems is one of the most important subroutines in many quantum machine learning algorithms. In this work, we present and analyze several other caveats in HHL algorithm, which have been ignored in the past. Thei...

Kishore Thapliyal·Mar 5, 2018

Nonclassical states, having no classical analogue, promise advantage in the performance in several fields of technology, such as computation, communication, sensing. This led to an escalated interest in the recent years for the generation and charact...

A. Opremcak, I. Pechenezhskiy, C. Howington +12 more·Mar 2, 2018

Counting the state of a qubit Operation of a quantum computer will be reliant on the ability to correct errors. This will typically require the fast, high-fidelity quantum nondemolition measurement of a large number of qubits. Opremcak et al. describ...

P. Sadowski·Mar 2, 2018

In this work we examine recently proposed distance-based classification method designed for near-term quantum processing units with limited resources. We further study possibilities to reduce the quantum resources without any efficiency decrease. We ...

Mathias Soeken, Thomas Häner, M. Rötteler·Mar 2, 2018

Recent developments in quantum hardware indicate that systems featuring more than 50 physical qubits are within reach. At this scale, classical simulation will no longer be feasible and there is a possibility that such quantum devices may outperform ...

Valentin Torggler, Philipp Aumann, H. Ritsch +1 more·Mar 2, 2018

The N-queens problem is to find the position of N queens on an N by N chess board such that no queens attack each other. The excluded diagonals N-queens problem is a variation where queens cannot be placed on some predefined fields along diagonals. T...

Xinyu Zhao, Xuedong Hu·Mar 2, 2018

With silicon being the go-to material for spin qubits, and motivated by the demand of a scalable quantum computer architecture for fast and reliable quantum information transfer on-chip, we study coherent electron transport in a silicon double quantu...