English
Related papers

Related papers: Cloning is as Hard as Learning for Stabilizer Stat…

200 papers

Cloning of observables, unlike standard cloning of states, aims at copying the information encoded in the statistics of a class of observables rather then on quantum states themselves. In such a process the emphasis is on the quantum…

Quantum Physics · Physics 2007-08-08 Alessandro Ferraro , Matteo G A Paris

A number of noncontextual models exist which reproduce different subsets of quantum theory and admit a no-cloning theorem. Therefore, if one chooses noncontextuality as one's notion of classicality, no-cloning cannot be regarded as a…

Quantum Physics · Physics 2020-04-29 Matteo Lostaglio , Gabriel Senno

The complete learning of an $n$-qubit quantum state requires samples exponentially in $n$. Several works consider subclasses of quantum states that can be learned in polynomial sample complexity such as stabilizer states or high-temperature…

Quantum Physics · Physics 2023-09-19 Liming Zhao , Naixu Guo , Ming-Xing Luo , Patrick Rebentrost

The inherent limitations of physical processes prevent the copying of arbitrary quantum states. Furthermore, even if we only aim to clone two distinct quantum states, it remains impossible unless they are mutually orthogonal. To overcome…

Quantum Physics · Physics 2025-07-24 Zhi-Hao Bi , Jing-Tao Qiu , Xiao-Dong Yu

We derive a lower bound for the optimal fidelity for deterministic cloning a set of n pure states. In connection with states estimation, we obtain a lower bound about average maximum correct states estimation probability.

Quantum Physics · Physics 2009-10-31 Chuan-Wei Zhang , Chuan-Feng Li , Guang-Can Guo

We examine the perfect cloning of non-local, orthogonal states with only local operations and classical communication. We provide a complete characterisation of the states that can be cloned under these restrictions, and their relation to…

Quantum Physics · Physics 2009-11-11 Alastair Kay , Marie Ericsson

Studying general quantum many-body systems is one of the major challenges in modern physics because it requires an amount of computational resources that scales exponentially with the size of the system.Simulating the evolution of a state,…

Quantum Physics · Physics 2018-07-03 Andrea Rocchetto , Edward Grant , Sergii Strelchuk , Giuseppe Carleo , Simone Severini

It is shown that any quantum operation that perfectly clones the entanglement of all maximally-entangled qubit pairs cannot preserve separability. This ``entanglement no-cloning'' principle naturally suggests that some approximate cloning…

Quantum Physics · Physics 2009-11-10 Louis-Philippe Lamoureux , Patrick Navez , Jaromir Fiurasek , Nicolas J. Cerf

The no-cloning theorem states that an unknown quantum state cannot be cloned exactly and deterministically due to the linearity of quantum mechanics. Associated with this theorem is the quantitative no-cloning limit that sets an upper bound…

While quantum state tomography is notoriously hard, most states hold little interest to practically-minded tomographers. Given that states and unitaries appearing in Nature are of bounded gate complexity, it is natural to ask if efficient…

Quantum Physics · Physics 2024-10-18 Haimeng Zhao , Laura Lewis , Ishaan Kannan , Yihui Quek , Hsin-Yuan Huang , Matthias C. Caro

We consider the quantum cloning of continuous variable entangled states. This is achieved by introducing two symmetric entanglement cloning machines (or e-cloners): a local e-cloner and a global e-cloner; where we look at the preservation…

Quantum Physics · Physics 2009-11-13 Christian Weedbrook , Nicolai B. Grosse , Thomas Symul , Ping Koy Lam , Timothy C. Ralph

The impossibility of perfect cloning and state estimation are two fundamental results in Quantum Mechanics. It has been conjectured that quantum cloning becomes equivalent to state estimation in the asymptotic regime where the number of…

Quantum Physics · Physics 2010-09-23 Joonwoo Bae , Antonio Acin

While the no-cloning theorem, which forbids the perfect copying of quantum states, is well-known as one of the defining features of quantum mechanics, the question of how well the theory allows a state to be cloned is yet to be completely…

Quantum Physics · Physics 2013-09-25 Alastair Kay , Ravishankar Ramanathan , Dagomir Kaszlikowski

We consider the problem of deterministically cloning quantum channels with respect to the best attainable rate and the highest quality, so-called optimal cloning. We demonstrate that cloning quantum states is, in-fact, equivalent to cloning…

The fidelity of a quantum transformation is strongly linked with the prior partial information of the state to be transformed. We illustrate this interesting point by proposing and demonstrating the superior cloning of coherent states with…

Quantum Physics · Physics 2009-11-13 Metin Sabuncu , Gerd Leuchs , Ulrik L. Andersen

Inspired by the work of Tsiamis et al. \cite{tsiamis2022learning}, in this paper we study the statistical hardness of learning to stabilize linear time-invariant systems. Hardness is measured by the number of samples required to achieve a…

Systems and Control · Electrical Eng. & Systems 2023-11-21 Xiong Zeng , Zexiang Liu , Zhe Du , Necmiye Ozay , Mario Sznaier

Quantum state tomography, the task of learning an unknown quantum state, is a fundamental problem in quantum information. In standard settings, the complexity of this problem depends significantly on the type of quantum state that one is…

Quantum Physics · Physics 2025-11-06 Maxime Meyer , Soumik Adhikary , Naixu Guo , Patrick Rebentrost

The states accepted by a quantum circuit are known as the witnesses for the quantum circuit's satisfiability. The assumption BQP does not equal QMA implies that no efficient algorithm exists for constructing a witness for a quantum circuit…

Quantum Physics · Physics 2024-11-19 Vojtěch Havlíček , Chinmay Nirkhe

We show that encrypted cloning of unknown quantum states is possible. Any number of encrypted clones of a qubit can be created through a unitary transformation, and each of the encrypted clones can be decrypted through a unitary…

Quantum Physics · Physics 2026-01-16 Koji Yamaguchi , Achim Kempf

Optimal quantum cloning is the process of making one or more copies of an arbitrary unknown input quantum state with the highest possible fidelity. All reported demonstrations of quantum cloning have so far been limited to copying…