Archives: Paper

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…

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…

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…

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…

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…

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…

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…

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-…

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…

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…

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…

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…

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…