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Related papers: Demonstration of a quantum nondemolition sum gate

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In this work, we report on a novel quantum gate approximation algorithm based on the application of parametric two-qubit gates in the synthesis process. The utilization of these parametric two-qubit gates in the circuit design allows us to…

Quantum Physics · Physics 2022-11-16 Péter Rakyta , Zoltán Zimborás

We experimentally demonstrate a virtual two-qubit gate and characterize it using quantum process tomography~(QPT). The virtual two-qubit gate decomposes an actual two-qubit gate into single-qubit unitary gates and projection gates in…

Hybrid qubits have recently drawn intensive attention in quantum computing. We here propose a method to implement a universal controlled-phase gate of two hybrid qubits via two three-dimensional (3D) microwave cavities coupled to a…

Quantum Physics · Physics 2019-10-23 Chui-Ping Yang , Zhen-Fei Zheng , Yu Zhang

Uniformly controlled one-qubit gates are quantum gates which can be represented as direct sums of two-dimensional unitary operators acting on a single qubit. We present a quantum gate array which implements any n-qubit gate of this type…

Quantum Physics · Physics 2009-11-10 Ville Bergholm , Juha J. Vartiainen , Mikko Mottonen , Martti M. Salomaa

The paper presents an analysis of entangling and nonlocal operations in a quantum nondemolition (QND) interaction between multimode light with orbital angular momentum and an atomic ensemble. A protocol consists of two QND operations with…

Quantum Physics · Physics 2024-10-17 E. A. Vashukevich , T. Yu. Golubeva

Quantum logic gates must perform properly when operating on their standard input basis states, as well as when operating on complex superpositions of these states. Experiments using superconducting qubits have validated the truth table for…

The gate version of quantum computation exploits several quantum key resources as superposition and entanglement to reach an outstanding performance. In the way, this theory was constructed adopting certain supposed processes imitating…

Quantum Physics · Physics 2017-06-13 Francisco Delgado

Quantum nondemolition (QND) measurements of photons is a much pursued endeavor in the field of quantum optics and quantum information processing. Here we propose a novel hybrid optoelectromechanical platform that integrates a cavity system…

Mesoscale and Nanoscale Physics · Physics 2021-01-04 Junjie Liu , Hsing-Ta Chen , Dvira Segal

The Zeno effect occurs in quantum systems when a very strong measurement is applied, which can alter the dynamics in non-trivial ways. Despite being dissipative, the dynamics stay coherent within any degenerate subspaces of the measurement.…

A universal quantum computing scheme, with a universal set of logical gates, is proposed based on networks of 1D quantum systems. The encoding of information is in terms of universal features of gapped phases, for which effective field…

Quantum Physics · Physics 2019-07-24 Dong-Sheng Wang

We demonstrate that complete set of gates can be realized in a DXD superconducting solid state quantum computer (quamputer), thereby proving its universality.

Quantum Physics · Physics 2009-10-31 Alexandre Blais , Alexandre M. Zagoskin

The promise of tremendous computational power, coupled with the development of robust error-correcting schemes, has fuelled extensive efforts to build a quantum computer. The requirements for realizing such a device are confounding:…

Quantum Physics · Physics 2011-08-17 J L O'Brien , G J Pryde , A G White , T C Ralph , D Branning

Quantum computing with qudits, quantum systems with $d > 2$ levels, offers a powerful extension beyond qubits, expanding the computational possibilities of quantum systems, allowing the simplification of the implementation of several…

Quantum Physics · Physics 2024-10-10 Francesco Pudda , Mario Chizzini , Luca Crippa

A proposal for applying non-adiabatic geometric phases to quantum computing, called the double-loop method [S.-L. Zhu and Z. D. Wang, Phys. Rev. A {\bf 67}, 022319 (2003)], is demonstrated in a liquid state NMR quantum computer. Using a…

Quantum Physics · Physics 2009-11-11 Yukihiro Ota , Yoshito Goto , Yasusi Kondo , Mikio Nakahara

We explore the feasibility of gate-based hybrid quantum computing using both discrete (qubit) and continuous (qumode) variables on trapped-ion platforms. Trapped-ion systems have demonstrated record one- and two-qubit gate fidelities and…

Quantum Physics · Physics 2025-07-24 Jack Y. Araz , Matt Grau , Jake Montgomery , Felix Ringer

We provide an analytic way to implement any arbitrary two-qubit unitary operation, given an entangling two-qubit gate together with local gates. This is shown to provide explicit construction of a universal quantum circuit that exactly…

Quantum Physics · Physics 2009-11-07 Jun Zhang , Jiri Vala , Shankar Sastry , K. Birgitta Whaley

We demonstrate complete characterization of a two-qubit entangling process - a linear optics controlled-NOT gate operating with coincident detection - by quantum process tomography. We use maximum-likelihood estimation to convert the…

Quantum Physics · Physics 2008-11-26 J. L. O'Brien , G. J. Pryde , A. Gilchrist , D. F. V. James , N. K. Langford , T. C. Ralph , A. G. White

We introduce quantum hybrid gates that act on qudits of different dimensions. In particular, we develop two representative two-qudit hybrid gates (SUM and SWAP) and many-qudit hybrid Toffoli and Fredkin gates. We apply the hybrid SUM gate…

Quantum Physics · Physics 2009-11-07 Jamil Daboul , Xiaoguang Wang , Barry C Sanders

The continuous-variable controlled-Z gate is a canonical two-mode gate for universal continuous-variable quantum computation. It is considered as one of the most fundamental continuous-variable quantum gates. Here we present a scheme for…

Quantum Physics · Physics 2015-05-27 Ming-Feng Wang , Nian-Quan Jiang , Qing-Li Jin , Yi-Zhuang Zheng

Measurement of quantum systems inevitably involves disturbance in various forms. Within the limits imposed by quantum mechanics, however, one can design an "ideal" projective measurement that does not introduce a back action on the measured…