Quantum

Paper

The shape of higher-dimensional state space: Bloch-ball analog for a qutrit

Christopher Eltschka, Marcus Huber, Simon Morelli, and Jens Siewert,

Quantum 5, 485 (2021).

Geometric intuition is a crucial tool to obtain deeper insight into many concepts of physics. A paradigmatic example of its power is the Bloch ball, the geometrical representation for the st…

Paper

Characterising and bounding the set of quantum behaviours in contextuality scenarios

Anubhav Chaturvedi, Máté Farkas, and Victoria J Wright,

Quantum 5, 484 (2021).

The predictions of quantum theory resist generalised noncontextual explanations. In addition to the foundational relevance of this fact, the particular extent to which quantum theory violate…

Paper

Variational Quantum Singular Value Decomposition

Xin Wang, Zhixin Song, and Youle Wang,

Quantum 5, 483 (2021).

Singular value decomposition is central to many problems in engineering and scientific fields. Several quantum algorithms have been proposed to determine the singular values and their associ…

Paper

Classical and quantum speed limits

Katarzyna Bolonek-Lasoń, Joanna Gonera, and Piotr Kosiński,

Quantum 5, 482 (2021).

The new bound on quantum speed limit (in terms of relative purity) is derived by applying the original Mandelstam-Tamm one to the evolution in the space of Hilbert-Schmidt operators acting i…

Paper

Quantum-accelerated multilevel Monte Carlo methods for stochastic differential equations in mathematical finance

Dong An, Noah Linden, Jin-Peng Liu, Ashley Montanaro, Changpeng Shao, and Jiasu Wang,

Quantum 5, 481 (2021).

Inspired by recent progress in quantum algorithms for ordinary and partial differential equations, we study quantum algorithms for stochastic differential equations (SDEs). Firstly we provid…

Paper

Hierarchy of quantum operations in manipulating coherence and entanglement

Hayata Yamasaki, Madhav Krishnan Vijayan, and Min-Hsiu Hsieh,

Quantum 5, 480 (2021).

Quantum resource theory under different classes of quantum operations advances multiperspective understandings of inherent quantum-mechanical properties, such as quantum coherence and quantu…

Paper

Warm-starting quantum optimization

Daniel J. Egger, Jakub Mareček, and Stefan Woerner,

Quantum 5, 479 (2021).

There is an increasing interest in quantum algorithms for problems of integer programming and combinatorial optimization. Classical solvers for such problems employ relaxations, which replac…

Paper

Experimental localisation of quantum entanglement through monitored classical mediator

Soham Pal, Priya Batra, Tanjung Krisnanda, Tomasz Paterek, and T. S. Mahesh,

Quantum 5, 478 (2021).

Quantum entanglement is a form of correlation between quantum particles that cannot be increased via local operations and classical communication. It has therefore been proposed that an incr…

Paper

Optimal Multi-port-based Teleportation Schemes

Marek Mozrzymas, Michał Studziński, and Piotr Kopszak,

Quantum 5, 477 (2021).

In this paper, we introduce optimal versions of a multi-port based teleportation scheme allowing to send a large amount of quantum information. We fully characterise probabilistic and determ…

Paper

Quantum marginal problem and incompatibility

Erkka Haapasalo, Tristan Kraft, Nikolai Miklin, and Roope Uola,

Quantum 5, 476 (2021).

One of the basic distinctions between classical and quantum mechanics is the existence of fundamentally incompatible quantities. Such quantities are present on all levels of quantum objects:…

Paper

Quantum Physical Unclonable Functions: Possibilities and Impossibilities

Myrto Arapinis, Mahshid Delavar, Mina Doosti, and Elham Kashefi,

Quantum 5, 475 (2021).

A Physical Unclonable Function (PUF) is a device with unique behaviour that is hard to clone hence providing a secure fingerprint. A variety of PUF structures and PUF-based applications have…

Paper

Visualizing the emission of a single photon with frequency and time resolved spectroscopy

Aleksei Sharafiev, Mathieu L. Juan, Oscar Gargiulo, Maximilian Zanner, Stephanie Wögerer, Juan José García-Ripoll, and Gerhard Kirchmair,

Quantum 5, 474 (2021).

At the dawn of Quantum Physics, Wigner and Weisskopf obtained a full analytical description (a $\textit{photon portrait}$) of the emission of a single photon by a two-level system, using the b…

Paper

Variational quantum solver employing the PDS energy functional

Bo Peng and Karol Kowalski,

Quantum 5, 473 (2021).

Recently a new class of quantum algorithms that are based on the quantum computation of the connected moment expansion has been reported to find the ground and excited state energies. In par…

Paper

Certifying dimension of quantum systems by sequential projective measurements

Adel Sohbi, Damian Markham, Jaewan Kim, and Marco Túlio Quintino,

Quantum 5, 472 (2021).

This work analyzes correlations arising from quantum systems subject to sequential projective measurements to certify that the system in question has a quantum dimension greater than some $d$.…

Paper

Witnessing Wigner Negativity

Ulysse Chabaud, Pierre-Emmanuel Emeriau, and Frédéric Grosshans,

Quantum 5, 471 (2021).

Negativity of the Wigner function is arguably one of the most striking non-classical features of quantum states. Beyond its fundamental relevance, it is also a necessary resource for quantum…

Paper

The group structure of dynamical transformations between quantum reference frames

Angel Ballesteros, Flaminia Giacomini, and Giulia Gubitosi,

Quantum 5, 470 (2021).

Recently, it was shown that when reference frames are associated to quantum systems, the transformation laws between such quantum reference frames need to be modified to take into account th…

Category: Paper