English
Related papers

Related papers: Universal super-replication of unitary gates

200 papers

We consider models of quantum computation that involve operations performed on some fixed resourceful quantum state. Examples that fit this paradigm include magic state injection and measurement-based approaches. We introduce a framework…

Quantum Physics · Physics 2025-08-18 Benjamin D. M. Jones , Noah Linden , Paul Skrzypczyk

The steady increase in control over individual quantum systems has backed the dream of a quantum technology that provides functionalities beyond any classical device. Two particularly promising applications have been explored during the…

Quantum Physics · Physics 2014-04-10 Andreas Reiserer , Norbert Kalb , Gerhard Rempe , Stephan Ritter

Though the no-cloning theorem [1] prohibits exact replication of arbitrary quantum states, there are many instances in quantum information processing and entanglement measurement in which a weaker form of cloning may be useful. Here, I…

Strongly Correlated Electrons · Physics 2016-10-19 Timothy H. Hsieh

We consider procedures to realize an approximate universal NOT gate in terms of average fidelity and fidelity deviation. The average fidelity indicates the optimality of operation on average, while the fidelity deviation does the…

Quantum Physics · Physics 2012-12-24 Jeongho Bang , Seung-Woo Lee , Hyunseok Jeong , Jinhyoung Lee

Non-invertible symmetries of a quantum field theory (QFT) are a natural generalization of unitary symmetries, but in which the product of operators does not satisfy a group multiplication law. We show that such symmetry operations on states…

High Energy Physics - Theory · Physics 2026-05-08 Jonathan J. Heckman , Rebecca J. Hicks , Chitraang Murdia

We propose and validate on real quantum computing hardware a new method for extended two-qubit gate set design, replacing iterative, fine calibration with fast characterization of a small number of gate parameters which are then tracked and…

Quantum states with nonlinear squeezing are a necessary resource for deterministic implementation of high-order quadrature phase gates that are, in turn, sufficient for advanced quantum information processing. We demonstrate that this class…

Quantum Physics · Physics 2021-07-15 Šimon Bräuer , Petr Marek

Ground-state quantum computers mimic quantum mechanical time evolution within the amplitudes of a time-independent quantum state. We explore the principles that constrain this mimicking. A no-cloning argument is found to impose strong…

Quantum Physics · Physics 2009-11-10 Ari Mizel

The no-cloning theorem forbids the creation of identical copies of qubits, thereby imposing strong limitations on quantum technologies. A recently-proposed protocol, encrypted cloning, showed, however, that the creation of perfect clones is…

We show that it is possible to clone quantum states to arbitrary accuracy in the presence of a Deutschian closed timelike curve (D-CTC), with a fidelity converging to one in the limit as the dimension of the CTC system becomes large---thus…

Quantum Physics · Physics 2014-07-31 Todd A. Brun , Mark M. Wilde , Andreas Winter

Although the quality of quantum bits (qubits) and quantum gates has been steadily improving, the available quantity of qubits has increased quite slowly. To address this important issue in quantum computing, we have demonstrated arbitrary…

Quantum Physics · Physics 2016-06-29 Yang Wang , Aishwarya Kumar , Tsung-Yao Wu , David S. Weiss

We consider the cloning of sequences of qubits prepared in the states used in the BB84 or 6-state quantum cryptography protocol, and show that the single-qubit fidelity is unaffected even if entire sequences of qubits are prepared in the…

Quantum Physics · Physics 2007-05-23 L. -P. Lamoureux , H. Bechmann-Pasquinucci , N. J. Cerf , N. Gisin , C. Macchiavello

The famous no-cloning principle has been shown recently to enable a number of uncloneable functionalities. Here we address for the first time unkeyed quantum uncloneablity, via the study of a complexity-theoretic tool that enables a…

Quantum Physics · Physics 2024-10-14 Anne Broadbent , Martti Karvonen , Sébastien Lord

Quantum computing can be realized with numerous different hardware platforms and computational protocols. A highly promising approach to foster scalability is to apply a photonic platform combined with a measurement-induced quantum…

We discuss techniques for producing, manipulating and measureing qubits encoded optically as vacuum and single photon states. We show that a universal set of non-deterministic gates can be constructed using linear optics and photon…

Quantum Physics · Physics 2009-11-07 A. P. Lund , T. C. Ralph

We discuss how to reconstruct quantum theory from operational postulates. In particular, the following postulates are consistent only with for classical probability theory and quantum theory. Logical Sharpness: There is a one-to-one map…

Quantum Physics · Physics 2013-03-20 Lucien Hardy

A proof is given, which relies on the commutator algebra of the unitary Lie groups, that quantum gates operating on just two bits at a time are sufficient to construct a general quantum circuit. The best previous result had shown the…

Condensed Matter · Physics 2009-10-22 David P. Divincenzo

No-Cloning and No-Deleting theorems are verified with the constraint on local state transformations via the existence of incomparable states. Assuming the existence of exact cloning or deleting operation defined on a minimum number of two…

Quantum Physics · Physics 2007-11-04 Amit Bhar , Indrani Chattopadhyay , Debasis Sarkar

The architecture of circuital quantum computers requires computing layers devoted to compiling high-level quantum algorithms into lower-level circuits of quantum gates. The general problem of quantum compiling is to approximate any unitary…

Quantum Physics · Physics 2021-09-21 Lorenzo Moro , Matteo G. A. Paris , Marcello Restelli , Enrico Prati

We study the minimal input sets which can determine completely the universal and the phase-covariant quantum cloning machines. We find that the universal quantum cloning machine, which can copy arbitrary input qubit equally well, however…

Quantum Physics · Physics 2013-01-01 Li Jing , Yi-Nan Wang , Han-Duo Shi , Liang-Zhu Mu , Heng Fan