Diagnosing Barren Plateaus with Tools from Quantum Optimal Control

Martin Larocca, Piotr Czarnik, Kunal Sharma, Gopikrishnan Muraleedharan, Patrick J. Coles, and M. Cerezo,

Quantum 6, 824 (2022).

Variational Quantum Algorithms (VQAs) have received considerable attention due to their potential for achieving near-term quantum advantage. However, more work is needed to understand their…

Steven Herbert,

Quantum 6, 823 (2022).

This paper proposes a method of quantum Monte Carlo integration that retains the full quadratic quantum advantage, without requiring any arithmetic or quantum phase estimation to be performe…

Peter Leviant, Qian Xu, Liang Jiang, and Serge Rosenblum,

Quantum 6, 821 (2022).

Bosonic qubits encoded in continuous-variable systems provide a promising alternative to two-level qubits for quantum computation and communication. So far, photon loss has been the dominant…

Yoav Afik and Juan Ramón Muñoz de Nova,

Quantum 6, 820 (2022).

Top quarks represent unique high-energy systems since their spin correlations can be measured, thus allowing to study fundamental aspects of quantum mechanics with qubits at high-energy coll…

Francesco Massa, Preeti Yadav, Amir Moqanaki, Walter O. Krawec, Paulo Mateus, Nikola Paunković, André Souto, and Philip Walther,

Quantum 6, 819 (2022).

Quantum key distribution, which allows two distant parties to share an unconditionally secure cryptographic key, promises to play an important role in the future of communication. For this r…

Sarah True and Alioscia Hamma,

Quantum 6, 818 (2022).

Entanglement is the defining characteristic of quantum mechanics. Bipartite entanglement is characterized by the von Neumann entropy. Entanglement is not just described by a number, however;…

Bartosz Regula,

Quantum 6, 817 (2022).

We develop two general approaches to characterising the manipulation of quantum states by means of probabilistic protocols constrained by the limitations of some quantum resource theory. Fir…

Yu Tong, Victor V. Albert, Jarrod R. McClean, John Preskill, and Yuan Su,

Quantum 6, 816 (2022).

Quantum many-body systems involving bosonic modes or gauge fields have infinite-dimensional local Hilbert spaces which must be truncated to perform simulations of real-time dynamics on class…

Mark A. Webster, Benjamin J. Brown, and Stephen D. Bartlett,

Quantum 6, 815 (2022).

We propose an extension to the Pauli stabiliser formalism that includes fractional $2\pi/N$ rotations around the $Z$ axis for some integer $N$. The resulting generalised stabiliser formalism – den…

Stavros Efthymiou, Marco Lazzarin, Andrea Pasquale, and Stefano Carrazza,

Quantum 6, 814 (2022).

Quantum technologies are moving towards the development of novel hardware devices based on quantum bits (qubits). In parallel to the development of quantum devices, efficient simulation tool…

Craig Gidney, Michael Newman, and Matt McEwen,

Quantum 6, 813 (2022).

We improve the planar honeycomb code by describing boundaries that need no additional physical connectivity, and by optimizing the shape of the qubit patch. We then benchmark the code using…

Lewis A. Clark, Bartosz Markowicz, and Jan Kołodyński,

Quantum 6, 812 (2022).

Optomechanical systems are rapidly becoming one of the most promising platforms for observing quantum behaviour, especially at the macroscopic level. Moreover, thanks to their state-of-the-a…

Zane M. Rossi and Isaac L. Chuang,

Quantum 6, 811 (2022).

Recent work shows that quantum signal processing (QSP) and its multi-qubit lifted version, quantum singular value transformation (QSVT), unify and improve the presentation of most quantum al…