English
Related papers

Related papers: Sequential quantum cloning under real-life conditi…

200 papers

We describe a unified framework of phase covariant multi user quantum transformations for d-dimensional quantum systems. We derive the optimal phase covariant cloning and transposition tranformations for multi phase states. We show that for…

Quantum Physics · Physics 2007-05-23 Francesco Buscemi , Giacomo Mauro D'Ariano , Chiara Macchiavello

We study the problem of universal quantum cloning -- taking several identical copies of a pure but unknown quantum state and producing further copies. While it is well known that it is impossible to perfectly reproduce the state, how well…

Quantum Physics · Physics 2016-08-09 Alastair Kay

We consider quantum devices for turning a finite number N of d-level quantum systems in the same unknown pure state \sigma into M>N systems of the same kind, in an approximation of the M-fold tensor product of the state \sigma. In a…

Quantum Physics · Physics 2015-06-26 M. Keyl , R. F. Werner

We investigate the universal asymmetric cloning of states in a Hilbert space of arbitrary dimension. We derive the class of optimal and fully asymmetric 1->3 cloners, which produce three copies, each having a different fidelity. A simple…

Quantum Physics · Physics 2007-05-23 Jaromir Fiurasek , Radim Filip , Nicolas J. Cerf

Characterising multi-time quantum processes is essential for analysing temporally correlated noise and for designing effective control and mitigation strategies. A complete operational description through multi-time process tomography…

Quantum Physics · Physics 2026-04-03 Abhinash Kumar Roy , Varun Srivastava , Christina Giarmatzi , Alexei Gilchrist

Digital quantum simulation on quantum systems require algorithms that can be implemented using finite quantum resources. Recent studies have demonstrated digital quantum simulation of open quantum systems on Noisy Intermediate-Scale Quantum…

Quantum Physics · Physics 2020-12-15 Pragati Gupta , C. M. Chandrashekar

Accurate prediction of mRNA secondary structure is critical for understanding gene expression, translation efficiency, and advancing mRNA-based therapeutics. However, the combinatorial complexity of possible foldings, especially in long…

AlphaFold has achieved groundbreaking advancements in protein structure prediction, exerting profound influence across biology, medicine, and drug discovery. However, its reliance on multiple sequence alignment (MSA) is inherently…

Quantum Physics · Physics 2025-06-03 Rong Chen , Quan-Xin Mei , Wen-Ding Zhao , Lin Yao , Hao-Xiang Yang , Shun-Yao Zhang , Jiao Chen , Hong-Lin Li

In classical computational chemistry, the coupled-cluster ansatz is one of the most commonly used $ab~initio$ methods, which is critically limited by its non-unitary nature. The unitary modification as an ideal solution to the problem is,…

Quantum Physics · Physics 2017-03-01 Yangchao Shen , Xiang Zhang , Shuaining Zhang , Jing-Ning Zhang , Man-Hong Yung , Kihwan Kim

Scaling up the number of qubits available on quantum processors remains technically demanding even in the long term; it is therefore crucial to clarify the number of qubits required to implement a given quantum operation. For the most…

Quantum Physics · Physics 2025-10-10 Kosuke Matsui , Jun-Yi Wu , Hayata Yamasaki , Min-Hsiu Hsieh , Mio Murao

Experimentally realizable quantum computers are rapidly approaching the threshold of quantum supremacy. Quantum Hamiltonian simulation promises to be one of the first practical applications for which such a device could demonstrate an…

Quantum Physics · Physics 2019-05-28 Rich Rines , Kevin Obenland , Isaac Chuang

Quantum machine learning seeks a computational advantage in data processing by evaluating functions of quantum states, such as their similarity, that can be classically intractable to compute. For quantum advantage to be possible, however,…

We review our recent work on the universal (i.e. input state independent) optimal quantum copying (cloning) of qubits. We present unitary transformations which describe the optimal cloning of a qubit and we present the corresponding quantum…

Quantum Physics · Physics 2007-05-23 Vladimir Buzek , Mark Hillery

The variational quantum eigensolver is one of the most promising algorithms for near-term quantum computers. It has the potential to solve quantum chemistry problems involving strongly correlated electrons, which are otherwise difficult to…

Quantum Physics · Physics 2023-07-18 Luogen Xu , James K. Freericks

We propose a deterministic scheme of generating genuine multiparty entangled states in quantum networks of arbitrary size having various geometric structures -- we refer to it as entanglement circulation. The procedure involves optimization…

Quantum Physics · Physics 2022-09-16 Pritam Halder , Ratul Banerjee , Srijon Ghosh , Amit Kumar Pal , Aditi Sen De

Molecular simulations are widely regarded as leading candidates to demonstrate quantum advantage--defined as the point at which quantum methods surpass classical approaches in either accuracy or scale. Yet the qubit counts and error rates…

The preparation of $n$-qubit quantum states is a cross-cutting subroutine for many quantum algorithms, and the effort to reduce its circuit complexity is a significant challenge. In the literature, the quantum state preparation algorithm by…

Quantum Physics · Physics 2026-02-09 Giacomo Belli , Michele Amoretti

Quantum devices, from simple fixed-function tools to the ultimate goal of a universal quantum computer, will require high quality, frequent repetition of a small set of core operations, such as the preparation of entangled states. These…

Quantum Physics · Physics 2018-05-22 Alastair Kay

Quantum chemistry provides a target for quantum simulation of considerable scientific interest and industrial importance. The majority of algorithms to date have been based on a second-quantized representation of the electronic structure…

Quantum Physics · Physics 2013-12-17 Borzu Toloui , Peter J. Love

We study state-dependent quantum cloning which can outperform universal cloning. This is possible by using some a priori information on a given quantum state to be cloned. Specifically, we propose a generalization and optical implementation…

Quantum Physics · Physics 2012-05-28 Karol Bartkiewicz , Adam Miranowicz