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Related papers: Optimized architectures for universal quantum stat…

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While quantum computers promise significant advantages, the complexity of quantum algorithms remains a major technological obstacle. We have developed and demonstrated an architecture-independent technique that simplifies adding control…

Quantum computation is based on implementing selected unitary transformations which represent algorithms. A generalized optimal control theory is used to find the driving field that generates a prespecified unitary transformation. The…

Quantum Physics · Physics 2009-11-07 Jose P. Palao , Ronnie Kosloff

Large-scale programmable photonic circuits are opening up new possibilities for information processing providing fast and energy-efficient means for matrix-vector multiplication. Here, we introduce a novel architecture of photonic circuits…

Optics · Physics 2025-09-19 S. A. Fldzhyan , M. Yu. Saygin , S. S. Straupe

In this paper, we propose an iterative algorithm using polar decomposition to approximate a channel characterized by a single unitary matrix based on input-output quantum state pairs. In limited data, we state and prove that the optimal…

Numerical Analysis · Mathematics 2025-06-27 Matthew M. Lin , Hao-Wei Huang , Bing-Ze Lu

In this paper, we report on experimental implementation of a linear-optical quantum router. Our device allows single-photon polarization-encoded qubits to be routed coherently into two spatial output modes depending on the state of two…

Quantum Physics · Physics 2018-09-12 Karol Bartkiewicz , Antonín Černoch , Karel Lemr

We develop an architecture of hybrid quantum solid-state processing unit for universal quantum computing. The architecture allows distant and nonidentical solid-state qubits in distinct physical systems to interact and work collaboratively.…

Quantum Physics · Physics 2012-05-08 Pei Pei , Feng-Yang Zhang , Chong Li , He-Shan Song

We address the question of how many maximally entangled photon pairs are needed in order to build up cluster states for quantum computing using the toolbox of linear optics. As the needed gates in dual-rail encoding are necessarily…

Quantum Physics · Physics 2015-06-26 K. Kieling , D. Gross , J. Eisert

As information carriers in quantum computing, photonic qubits have the advantage of undergoing negligible decoherence. However, the absence of any significant photon-photon interaction is problematic for the realization of non-trivial…

The preparation of quantum states, especially cooling, is a fundamental technology for nanoscale devices. The past decade has seen important results related to both the limits of state transformation and the limits to their efficiency --…

Quantum Physics · Physics 2024-12-11 Ralph Silva , Pharnam Bakhshinezhad , Fabien Clivaz

Linear optical elements are pivotal instruments in the manipulation of classical and quantum states of light. The vast progress in integrated quantum photonic technology enables the implementation of large numbers of such elements on chip…

Quantum Physics · Physics 2016-10-10 Max Tillmann , Christian Schmidt , Philip Walther

Implementing a qubit quantum computer in continuous-variable systems conventionally requires the engineering of specific interactions according to the encoding basis states. In this work, we present a unified formalism to conduct universal…

Quantum Physics · Physics 2016-09-06 Hoi-Kwan Lau , Martin B. Plenio

Realising a global quantum network requires combining individual strengths of different quantum systems to perform universal tasks, notably using flying and stationary qubits. However, transferring coherently quantum information between…

Recent reports of large photonic nonlinearities in integrated photonic devices, using the strong excitonic light-matter coupling in semiconductors, necessitate a tailored design framework for quantum processing in the limit of low photon…

Quantum Physics · Physics 2026-05-14 Mathias Van Regemortel , Thomas Van Vaerenbergh

Quantum computers have the capability of out-performing their classical counterparts for certain computational problems. Several scalable quantum computing architectures have been proposed. An attractive architecture is a large set of…

The decomposition of arbitrary unitary transformations into sequences of simpler, physically realizable operations is a foundational problem in quantum information science, quantum control, and linear optics. We establish a 1D Quantum Field…

Quantum Physics · Physics 2026-03-20 Javier Álvarez-Vizoso , David Barral

High-dimensional biphoton states are promising resources for quantum applications, ranging from high-dimensional quantum communications to quantum imaging. A pivotal task is fully characterising these states, which is generally…

Quantum Physics · Physics 2023-02-20 Danilo Zia , Nazanin Dehghan , Alessio D'Errico , Fabio Sciarrino , Ebrahim Karimi

Here, we numerically simulate probabilistic elementary entangling operations between rail-encoded photons for the purpose of scalable universal quantum computation or communication. We propose grouping logical qubits into single-photon…

Quantum Physics · Physics 2018-01-24 Jake A. Smith , Lev Kaplan

The concept of directionally unbiased optical multiports is introduced, in which photons may reflect back out the input direction. A linear-optical implementation is described, and the simplest three-port version studied. Symmetry arguments…

Quantum Physics · Physics 2016-04-29 David S. Simon , Casey A. Fitzpatrick , Alexander V. Sergienko

We describe in detail the application of four qubit cluster states, built on the simultaneous entanglement of two photons in the degrees of freedom of polarization and linear momentum, for the realization of a complete set of basic one-way…

Quantum Physics · Physics 2008-11-05 Giuseppe Vallone , Enrico Pomarico , Francesco De Martini , Paolo Mataloni

This paper presents a scheme for linear-optical implementation of a programmable quantum router. Polarization encoded photon qubit is coherently routed to various spatial modes according to the state of several control qubits. In our…

Quantum Physics · Physics 2013-07-01 Karel Lemr , Antonín Černoch