Quantum

Quantum has published 566 Papers in 5 Volumes, as well as 61 Views in Quantum Views.

Simultaneous Perturbation Stochastic Approximation of the Quantum Fisher Information

Julien Gacon, Christa Zoufal, Giuseppe Carleo, and Stefan Woerner,

Quantum 5, 567 (2021).

The Quantum Fisher Information matrix (QFIM) is a central metric in promising algorithms, such as Quantum Natural Gradient Descent and Variational Quantum Imaginary Time Evolution. Computing…

Paper

Faster Coherent Quantum Algorithms for Phase, Energy, and Amplitude Estimation

Patrick Rall,

Quantum 5, 566 (2021).

We consider performing phase estimation under the following conditions: we are given only one copy of the input state, the input state does not have to be an eigenstate of the unitary, and t…

Paper

Multidimensional cluster states using a single spin-photon interface coupled strongly to an intrinsic nuclear register

Cathryn P. Michaels, Jesús Arjona Martínez, Romain Debroux, Ryan A. Parker, Alexander M. Stramma, Luca I. Huber, Carola M. Purser, Mete Atatüre, and Dorian A. Gangloff,

Quantum 5, 565 (2021).

Photonic cluster states are a powerful resource for measurement-based quantum computing and loss-tolerant quantum communication. Proposals to generate multi-dimensional lattice cluster state…

Paper

Dynamically Generated Logical Qubits

Matthew B. Hastings and Jeongwan Haah,

Quantum 5, 564 (2021).

We present a quantum error correcting code with $\textit{dynamically generated logical qubits}$. When viewed as a subsystem code, the code has no logical qubits. Nevertheless, our measurement…

Paper

Quantum-classical correspondence of a system of interacting bosons in a triple-well potential

E. R. Castro, Jorge Chávez-Carlos, I. Roditi, Lea F. Santos, and Jorge G. Hirsch,

Quantum 5, 563 (2021).

We study the quantum-classical correspondence of an experimentally accessible system of interacting bosons in a tilted triple-well potential. With the semiclassical analysis, we get a better…

Paper

Trapping Sets of Quantum LDPC Codes

Nithin Raveendran and Bane Vasić,

Quantum 5, 562 (2021).

Iterative decoders for finite length quantum low-density parity-check (QLDPC) codes are attractive because their hardware complexity scales only linearly with the number of physical qubits.…

Paper

Entangled symmetric states and copositive matrices

Carlo Marconi, Albert Aloy, Jordi Tura, and Anna Sanpera,

Quantum 5, 561 (2021).

Entanglement in symmetric quantum states and the theory of copositive matrices are intimately related concepts. For the simplest symmetric states, i.e., the diagonal symmetric (DS) states, i…

Paper

The Quantum Supremacy Tsirelson Inequality

William Kretschmer,

Quantum 5, 560 (2021).

A leading proposal for verifying near-term quantum supremacy experiments on noisy random quantum circuits is linear cross-entropy benchmarking. For a quantum circuit $C$ on $n$ qubits and a samp…

Perspective

Fisher Information: A Crucial Tool for NISQ Research

Kishor Bharti,

Quantum Views 5, 61 (2021).

Quantum computers available today consist of around a few dozen qubits. Each quantum gate operation is afflicted by a certain level of noise, and hence the computations are restricted…

Paper

Qulacs: a fast and versatile quantum circuit simulator for research purpose

Yasunari Suzuki, Yoshiaki Kawase, Yuya Masumura, Yuria Hiraga, Masahiro Nakadai, Jiabao Chen, Ken M. Nakanishi, Kosuke Mitarai, Ryosuke Imai, Shiro Tamiya, Takahiro Yamamoto, Tennin Yan, Toru Kawakubo, Yuya O. Nakagawa, Yohei Ibe, Youyuan Zhang, Hirotsugu Yamashita, Hikaru Yoshimura, Akihiro Hayashi, and Keisuke Fujii,

Quantum 5, 559 (2021).

To explore the possibilities of a near-term intermediate-scale quantum algorithm and long-term fault-tolerant quantum computing, a fast and versatile quantum circuit simulator is needed. Her…

Paper