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Category: Paper

Paper

Quantum routing with fast reversals

Aniruddha Bapat, Andrew M. Childs, Alexey V. Gorshkov, Samuel King, Eddie Schoute, and Hrishee Shastri,

Quantum 5, 533 (2021).

We present methods for implementing arbitrary permutations of qubits under interaction constraints. Our protocols make use of previous methods for rapidly reversing the order of qubits along…

Paper

Reachability Deficits in Quantum Approximate Optimization of Graph Problems

V. Akshay, H. Philathong, I. Zacharov, and J. Biamonte,

Quantum 5, 532 (2021).

The quantum approximate optimization algorithm (QAOA) has become a cornerstone of contemporary quantum applications development. Here we show that the $density$ of problem constraints versus p…

Paper

Towards understanding the power of quantum kernels in the NISQ era

Xinbiao Wang, Yuxuan Du, Yong Luo, and Dacheng Tao,

Quantum 5, 531 (2021).

A key problem in the field of quantum computing is understanding whether quantum machine learning (QML) models implemented on noisy intermediate-scale quantum (NISQ) machines can achieve qua…

Paper

Quantum reference frame transformations as symmetries and the paradox of the third particle

Marius Krumm, Philipp A. Höhn, and Markus P. Müller,

Quantum 5, 530 (2021).

In a quantum world, reference frames are ultimately quantum systems too – but what does it mean to "jump into the perspective of a quantum particle"? In this work, we show that quantum refer…

Paper

Quantum algorithms for escaping from saddle points

Chenyi Zhang, Jiaqi Leng, and Tongyang Li,

Quantum 5, 529 (2021).

We initiate the study of quantum algorithms for escaping from saddle points with provable guarantee. Given a function $f\colon\mathbb{R}^{n}\to\mathbb{R}$, our quantum algorithm outputs an…

Paper

Many-Body Quantum Zeno Effect and Measurement-Induced Subradiance Transition

Alberto Biella and Marco Schiró,

Quantum 5, 528 (2021).

It is well known that by repeatedly measuring a quantum system it is possible to completely freeze its dynamics into a well defined state, a signature of the quantum Zeno effect. Here we sho…

Paper

Poisson Quantum Information

Mankei Tsang,

Quantum 5, 527 (2021).

By taking a Poisson limit for a sequence of rare quantum objects, I derive simple formulas for the Uhlmann fidelity, the quantum Chernoff quantity, the relative entropy, and the Helstrom inf…

Paper

Quadrature protection of squeezed states in a one-dimensional photonic topological insulator

Joaquin Medina Dueñas, Gabriel O’Ryan Pérez, Carla Hermann-Avigliano, and Luis E. F. Foa Torres,

Quantum 5, 526 (2021).

What is the role of topology in the propagation of quantum light in photonic lattices? We address this question by studying the propagation of squeezed states in a topological one-dimensiona…

Paper

Effect of environment on the interferometry of clocks

Harshit Verma, Magdalena Zych, and Fabio Costa,

Quantum 5, 525 (2021).

Quantum interference of "clocks", namely of particles with time-evolving internal degrees of freedom (DOFs), is a promising avenue to test genuine general relativistic effects in quantum sys…

Paper

Generalized probability rules from a timeless formulation of Wigner’s friend scenarios

Veronika Baumann, Flavio Del Santo, Alexander R. H. Smith, Flaminia Giacomini, Esteban Castro-Ruiz, and Caslav Brukner,

Quantum 5, 524 (2021).

The quantum measurement problem can be regarded as the tension between the two alternative dynamics prescribed by quantum mechanics: the unitary evolution of the wave function and the state-…

Paper

Borromean states in discrete-time quantum walks

Marcin Markiewicz, Marcin Karczewski, and Pawel Kurzynski,

Quantum 5, 523 (2021).

In the right conditions, removing one particle from a multipartite bound state can make it fall apart. This feature, known as the "Borromean property", has been recently demonstrated experim…

Paper

Operational applications of the diamond norm and related measures in quantifying the non-physicality of quantum maps

Bartosz Regula, Ryuji Takagi, and Mile Gu,

Quantum 5, 522 (2021).

Although quantum channels underlie the dynamics of quantum states, maps which are not physical channels — that is, not completely positive — can often be encountered in settings such as enta…

Paper

New perspectives on covariant quantum error correction

Sisi Zhou, Zi-Wen Liu, and Liang Jiang,

Quantum 5, 521 (2021).

Covariant codes are quantum codes such that a symmetry transformation on the logical system could be realized by a symmetry transformation on the physical system, usually with limited capabi…

Paper

The arrow of time in operational formulations of quantum theory

Andrea Di Biagio, Pietro Donà, and Carlo Rovelli,

Quantum 5, 520 (2021).

The operational formulations of quantum theory are drastically time oriented. However, to the best of our knowledge, microscopic physics is time-symmetric. We address this tension by showing…

Paper

Diagonal unitary and orthogonal symmetries in quantum theory

Satvik Singh and Ion Nechita,

Quantum 5, 519 (2021).

We analyze bipartite matrices and linear maps between matrix algebras, which are respectively, invariant and covariant, under the diagonal unitary and orthogonal groups' actions. By presenti…

Paper

Classical causal models cannot faithfully explain Bell nonlocality or Kochen-Specker contextuality in arbitrary scenarios

J. C. Pearl and E. G. Cavalcanti,

Quantum 5, 518 (2021).

In a recent work, it was shown by one of us (EGC) that Bell-Kochen-Specker inequality violations in phenomena satisfying the no-disturbance condition (a generalisation of the no-signalling c…

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Coordinating editors

  • Carlo Beenakker
  • Eric Cavalcanti
  • Sevag Gharibian
  • Ujjwal Sen
  • Ronald de Wolf

Editors

  • Elizabeth Agudelo
  • Álvaro Alhambra
  • Fabio Anza
  • Mateus Araújo
  • Remigiusz Augusiak
  • Flavio Baccari
  • Miriam Backens
  • Aleksandrs Belovs
  • Alessio Benavoli
  • Kishor Bharti
  • Andrea Di Biagio
  • Michele Campisi
  • Ángela Capel
  • Angelo Carollo
  • Marco Cerezo
  • Ulysse Chabaud
  • Francesco Ciccarello
  • Ivan Contreras
  • Luis A. Correa
  • Eleanor Crane
  • Borivoje Dakic
  • Abhinav Deshpande
  • Vedran Dunjko
  • Thomas Elliott
  • Dax Enshan Koh
  • Paul Erker
  • Philippe Faist
  • Di Fang
  • Máté Farkas
  • Nicolai Friis
  • Christos Gagatsos
  • Diego García-Martín
  • Roohollah Ghobadi
  • Géza Giedke
  • Aaron Goldberg
  • Alioscia Hamma
  • Felix Huber
  • Martin Kliesch
  • Ravi Kunjwal
  • Felix Leditzky
  • Lorenzo Leone
  • Tongyang Li
  • Jin-Peng Liu
  • Yuan Liu
  • Maximilian Lock
  • Leon Loveridge
  • Tommaso Macrì
  • Daniel Malz
  • Atul Mantri
  • Milad Marvian
  • Daniel McNulty
  • Saeed Mehraban
  • Pérola Milman
  • Mark Mitchison
  • Tomoyuki Morimae
  • Ion Nechita
  • Patrick Rebentrost
  • Narayanan Rengaswamy
  • Joschka Roffe
  • Dennis Rätzel
  • Mohan Sarovar
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  • Philipp Schindler
  • Alexander Schuckert
  • Gael Sentís
  • Jiangwei Shang
  • Changpeng Shao
  • Kunal Sharma
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  • Michael Vasmer
  • Petros Wallden
  • Xin Wang
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  • Alexander Wilce
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  • Ruizhe Zhang

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  • Christian Gogolin
  • Marcus Huber
  • Lídia del Rio

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  • Antonio Acín
  • Anne Broadbent
  • Harry Buhrman
  • Daniel Burgarth
  • Guido Burkard
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  • Debbie Leung
  • Chaoyang Lu
  • Chiara Macchiavello
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  • Joseph M. Renes
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