Quantum

Paper

Maximum $N$-body correlations do not in general imply genuine multipartite entanglement

Christopher Eltschka and Jens Siewert,

Quantum 4, 229 (2020).

The existence of correlations between the parts of a quantum system on the one hand, and entanglement between them on the other, are different properties. Yet, one intuitively would identify…

Paper

Computational universality of symmetry-protected topologically ordered cluster phases on 2D Archimedean lattices

Austin K. Daniel, Rafael N. Alexander, and Akimasa Miyake,

Quantum 4, 228 (2020).

What kinds of symmetry-protected topologically ordered (SPTO) ground states can be used for universal measurement-based quantum computation in a similar fashion to the 2D cluster state? 2D S…

Paper

Completely positive master equation for arbitrary driving and small level spacing

Evgeny Mozgunov and Daniel Lidar,

Quantum 4, 227 (2020).

Markovian master equations are a ubiquitous tool in the study of open quantum systems, but deriving them from first principles involves a series of compromises. On the one hand, the Redfield…

Paper

Data re-uploading for a universal quantum classifier

Adrián Pérez-Salinas, Alba Cervera-Lierta, Elies Gil-Fuster, and José I. Latorre,

Quantum 4, 226 (2020).

A single qubit provides sufficient computational capabilities to construct a universal quantum classifier when assisted with a classical subroutine. This fact may be surprising since a singl…

Paper

A change of perspective: switching quantum reference frames via a perspective-neutral framework

Augustin Vanrietvelde, Philipp A. Hoehn, Flaminia Giacomini, and Esteban Castro-Ruiz,

Quantum 4, 225 (2020).

Treating reference frames fundamentally as quantum systems is inevitable in quantum gravity and also in quantum foundations once considering laboratories as physical systems. Both fields the…

Paper

Quantized Three-Ion-Channel Neuron Model for Neural Action Potentials

Tasio Gonzalez-Raya, Enrique Solano, and Mikel Sanz,

Quantum 4, 224 (2020).

The Hodgkin-Huxley model describes the conduction of the nervous impulse through the axon, whose membrane's electric response can be described employing multiple connected electric circuits…

Paper

From estimation of quantum probabilities to simulation of quantum circuits

Hakop Pashayan, Stephen D. Bartlett, and David Gross,

Quantum 4, 223 (2020).

Investigating the classical simulability of quantum circuits provides a promising avenue towards understanding the computational power of quantum systems. Whether a class of quantum circuits…

Paper

Ideal Projective Measurements Have Infinite Resource Costs

Yelena Guryanova, Nicolai Friis, and Marcus Huber,

Quantum 4, 222 (2020).

We show that it is impossible to perform ideal projective measurements on quantum systems using finite resources. We identify three fundamental features of ideal projective measurements and…

Paper

Quantum algorithms and lower bounds for convex optimization

Shouvanik Chakrabarti, Andrew M. Childs, Tongyang Li, and Xiaodi Wu,

Quantum 4, 221 (2020).

While recent work suggests that quantum computers can speed up the solution of semidefinite programs, little is known about the quantum complexity of more general convex optimization. We pre…

Paper

Convex optimization using quantum oracles

Joran van Apeldoorn, András Gilyén, Sander Gribling, and Ronald de Wolf,

Quantum 4, 220 (2020).

We study to what extent quantum algorithms can speed up solving convex optimization problems. Following the classical literature we assume access to a convex set via various oracles, and we…

Paper

Hypergraph framework for irreducible noncontextuality inequalities from logical proofs of the Kochen-Specker theorem

Ravi Kunjwal,

Quantum 4, 219 (2020).

Kochen-Specker (KS) theorem reveals the inconsistency between quantum theory and any putative underlying model of it satisfying the constraint of KS-noncontextuality. A logical proof of the…

Paper

The ZX calculus is a language for surface code lattice surgery

Niel de Beaudrap and Dominic Horsman,

Quantum 4, 218 (2020).

A leading choice of error correction for scalable quantum computing is the surface code with lattice surgery. The basic lattice surgery operations, the merging and splitting of logical qubit…

Paper

Homotopical approach to quantum contextuality

Cihan Okay and Robert Raussendorf,

Quantum 4, 217 (2020).

We consider the phenomenon of quantum mechanical contextuality, and specifically parity-based proofs thereof. Mermin’s square and star are representative examples. Part of the information in…

Paper

Parameter regimes for surpassing the PLOB bound with error-corrected qudit repeaters

Daniel Miller, Timo Holz, Hermann Kampermann, and Dagmar Bruß,

Quantum 3, 216 (2019).

A potential quantum internet would open up the possibility of realizing numerous new applications, including provably secure communication. Since losses of photons limit long-distance, direc…

Paper

Optimizing Quantum Error Correction Codes with Reinforcement Learning

Hendrik Poulsen Nautrup, Nicolas Delfosse, Vedran Dunjko, Hans J. Briegel, and Nicolai Friis,

Quantum 3, 215 (2019).

Quantum error correction is widely thought to be the key to fault-tolerant quantum computation. However, determining the most suited encoding for unknown error channels or specific laborator…

Paper

An initialization strategy for addressing barren plateaus in parametrized quantum circuits

Edward Grant, Leonard Wossnig, Mateusz Ostaszewski, and Marcello Benedetti,

Quantum 3, 214 (2019).

Parametrized quantum circuits initialized with random initial parameter values are characterized by barren plateaus where the gradient becomes exponentially small in the number of qubits. In…

Category: Paper