Archives: Paper

Markus S. Kesselring, Fernando Pastawski, Jens Eisert, and Benjamin J. Brown,

Quantum 2, 101 (2018). https://doi.org/10.22331/q-2018-10-19-101

The color code is both an interesting example of an exactly solved topologically ordered phase of matter and also among the most promising candidate models to realize fault-tolerant quantum…

María García Díaz, Kun Fang, Xin Wang, Matteo Rosati, Michalis Skotiniotis, John Calsamiglia, and Andreas Winter,

Quantum 2, 100 (2018). https://doi.org/10.22331/q-2018-10-19-100

Coherent superposition is a key feature of quantum mechanics that underlies the advantage of quantum technologies over their classical counterparts. Recently, coherence has been recast as a…

Yuan Su and John Watrous,

Quantum 2, 98 (2018). https://doi.org/10.22331/q-2018-10-04-98

The $\textit{quantum strategy}$ (or $\textit{quantum combs}$) framework is a useful tool for reasoning about interactions among entities that process and exchange quantum information over th…

A. González-Tudela and J. I. Cirac,

Quantum 2, 97 (2018). https://doi.org/10.22331/q-2018-10-01-97

Quantum emitters coupled to structured photonic reservoirs experience unconventional individual and collective dynamics emerging from the interplay between dimensionality and non-trivial pho…

T.J. Volkoff and K.B. Whaley,

Quantum 2, 96 (2018). https://doi.org/10.22331/q-2018-10-01-96

For both unitary and open qubit dynamics, we compare asymmetry monotone-based bounds on the minimal time required for an initial qubit state to evolve to a final qubit state from which it is…

Johannes Bausch and Elizabeth Crosson,

Quantum 2, 94 (2018). https://doi.org/10.22331/q-2018-09-19-94

Feynman's circuit-to-Hamiltonian construction connects quantum computation and ground states of many-body quantum systems. Kitaev applied this construction to demonstrate QMA-completeness of…

Rui Chao, Ben W. Reichardt, Chris Sutherland, and Thomas Vidick,

Quantum 2, 92 (2018). https://doi.org/10.22331/q-2018-09-03-92

Bell-inequality violations establish that two systems share some quantum entanglement. We give a simple test to certify that two systems share an asymptotically large amount of entanglement,…

Mikel Sanz, Witlef Wieczorek, Simon Gröblacher, and Enrique Solano,

Quantum 2, 91 (2018). https://doi.org/10.22331/q-2018-09-03-91

The dynamical Casimir effect is an intriguing phenomenon in which photons are generated from vacuum due to a non-adiabatic change in some boundary conditions. In particular, it connects the…

Gus Gutoski, Ansis Rosmanis, and Jamie Sikora,

Quantum 2, 89 (2018). https://doi.org/10.22331/q-2018-09-03-89

We introduce a definition of the fidelity function for multi-round quantum strategies, which we call the $\textit{strategy fidelity}$, that is a generalization of the fidelity function for q…

Christina Knapp, Michael Beverland, Dmitry I. Pikulin, and Torsten Karzig,

Quantum 2, 88 (2018). https://doi.org/10.22331/q-2018-09-03-88

Majorana-based quantum computing seeks to use the non-local nature of Majorana zero modes to store and manipulate quantum information in a topologically protected way. While noise is anticip…

Benjamin Dive, Alexander Pitchford, Florian Mintert, and Daniel Burgarth,

Quantum 2, 80 (2018). https://doi.org/10.22331/q-2018-08-08-80

Quantum simulators, machines that can replicate the dynamics of quantum systems, are being built as useful devices and are seen as a stepping stone to universal quantum computers. A key diff…

Adam Winick, Norbert Lütkenhaus, and Patrick J. Coles,

Quantum 2, 77 (2018). https://doi.org/10.22331/q-2018-07-26-77

In this work, we present a reliable, efficient, and tight numerical method for calculating key rates for finite-dimensional quantum key distribution (QKD) protocols. We illustrate our approa…

Felix A. Pollock and Kavan Modi,

Quantum 2, 76 (2018). https://doi.org/10.22331/q-2018-07-11-76

Memory effects in open quantum dynamics are often incorporated in the equation of motion through a superoperator known as the memory kernel, which encodes how past states affect future dynam…

Filippo M. Miatto, Michael Epping, and Norbert Lütkenhaus,

Quantum 2, 75 (2018). https://doi.org/10.22331/q-2018-07-05-75

Quantum information degrades over distance due to the unavoidable imperfections of the transmission channels, with loss as the leading factor. This simple fact hinders quantum communication,…

Armin Tavakoli, Géraldine Haack, Marcus Huber, Nicolas Brunner, and Jonatan Bohr Brask,

Quantum 2, 73 (2018). https://doi.org/10.22331/q-2018-06-13-73

We present a scheme for dissipatively generating maximal entanglement in a heralded manner. Our setup requires incoherent interactions with two thermal baths at different temperatures, but n…