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Related papers: Input independence

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The conventional paradigm of quantum computing is discrete: it utilizes discrete sets of gates to realize bitstring-to-bitstring mappings, some of them arguably intractable for classical computers. In parameterized quantum approaches, the…

Quantum Physics · Physics 2025-12-12 Adrián Pérez-Salinas , Mahtab Yaghubi Rad , Alice Barthe , Vedran Dunjko

We describe in detail a general strategy for implementing a conditional geometric phase between two spins. Combined with single-spin operations, this simple operation is a universal gate for quantum computation, in that any unitary…

Quantum Physics · Physics 2015-06-26 A. Ekert , M. Ericsson , P. Hayden , H. Inamori , J. A. Jones , D. K. L. Oi , V. Vedral

Using electrostatic gates to control the electron positions, we present a new controlled-NOT gate based on quantum dots. The qubit states are chosen to be the spin states of an excess conductor electron in the quantum dot; and the main…

Quantum Physics · Physics 2007-05-23 Cyrus C. Y. Lin , Chopin Soo , Yin-Zhong Wu , Wei-Min Zhang

The hypothesis of quantum self-interference is not directly observable, but has at least three necessary implications. First, a quantum entity must have no less than two open paths. Second, the size of the interval between any two…

Quantum Physics · Physics 2009-11-10 Ghenadie N. Mardari

Unlike fixed designs, programmable circuit designs support an infinite number of operators. The functionality of a programmable circuit can be altered by simply changing the angle values of the rotation gates in the circuit. Here, we…

Quantum Physics · Physics 2012-12-27 Anmer Daskin , Ananth Grama , Giorgos Kollias , Sabre Kais

We propose some formulations of the notion of "operational independence" of two subsystems of a larger quantum system and clarify their relation to other independence concepts in the literature. In addition, we indicate why the operational…

Quantum Physics · Physics 2010-11-09 Miklos Redei , Stephen J. Summers

We prove that for any $n$-qubit unitary transformation $U$ and for any $r = 2^{o(n / \log n)}$, there exists a quantum circuit to implement $U^{\otimes r}$ with at most $O(4^n)$ gates. This asymptotically equals the number of gates needed…

Quantum Physics · Physics 2025-09-18 William Kretschmer

We describe how one may go about performing quantum computation with arbitrary "quantum stuff", as long as it has some basic physical properties. Imagine a long strip of stuff, equipped with regularly spaced wires to provide input settings…

Quantum Physics · Physics 2019-12-03 Lucien Hardy , Adam G. M. Lewis

We propose a quantum algorithm that emulates the action of an unknown unitary transformation on a given input state, using multiple copies of some unknown sample input states of the unitary and their corresponding output states. The…

Quantum Physics · Physics 2024-03-27 Iman Marvian , Seth Lloyd

The theory of quantum computation is presented in a self contained way from a computer science perspective. The basics of classical computation and quantum mechanics is reviewed. The circuit model of quantum computation is presented in…

Quantum Physics · Physics 2007-05-23 Anders K. H. Bengtsson

An algorithm for quantum computing Hamiltonian cycles of simple, cubic, bipartite graphs is discussed. It is shown that it is possible to evolve a quantum computer into an entanglement of states which map onto the set of all possible paths…

Quantum Physics · Physics 2007-05-23 T. Rudolph

We define the idea of {\it real path quantum theory}, a realist generalisation of quantum theory in which it is postulated that the configuration space path actually followed by a closed quantum system is probabilistically chosen. This is…

Quantum Physics · Physics 2013-05-29 Adrian Kent

We argue that the demand of background independence in a quantum theory of gravity calls for an extension of standard geometric quantum mechanics. We discuss a possible kinematical and dynamical generalization of the latter by way of a…

High Energy Physics - Theory · Physics 2008-11-26 Djordje Minic , Chia-Hsiung Tze

Any unitary transformation of quantum computational networks is explicitly decomposed, in an exact and unified form, into a sequence of a limited number of one-qubit quantum gates and the two-qubit diagonal gates that have diagonal unitary…

Quantum Physics · Physics 2007-05-23 Xijia Miao

We propose an approach to quantum computing in which quantum gate strengths are parametrized by quantum degrees of freedom, and the capability of the quantum computer to perform desired tasks is monitored and gradually improved by…

Quantum Physics · Physics 2009-11-25 Soren Gammelmark , Klaus Molmer

In this note we point out the fact that the proper conceptual setting of quantum computation is the theory of Linear Time Invariant systems. To convince readers of the utility of the approach, we introduce a new model of computation based…

Quantum Physics · Physics 2007-05-23 H. Gopalkrishna Gadiyar , K. M. Sangeeta Maini , R. Padma , H. S. Sharatchandra

Quantifying the resources available to a quantum computer appears to be necessary to separate quantum from classical computation. Among them, entanglement, nonstabilizerness and coherence are arguably of great significance. We introduce…

We introduce a general statistical learning theory for processes that take as input a classical random variable and output a quantum state. Our setting is motivated by the practical situation in which one desires to learn a quantum process…

Quantum Physics · Physics 2025-02-27 Marco Fanizza , Yihui Quek , Matteo Rosati

We investigate how to carry out universal quantum computation deterministically with free electrons in decoherence-free subspace by using polarizing beam splitters, charge detectors, and single-spin rotations. Quantum information in our…

Quantum Physics · Physics 2007-10-23 X. L. Zhang , M. Feng , K. L. Gao

Suppose that we are given a quantum computer programmed ready to perform a computation if it is switched on. Counterfactual computation is a process by which the result of the computation may be learnt without actually running the computer.…

Quantum Physics · Physics 2015-06-26 Graeme Mitchison , Richard Jozsa