scholarly journals A quantum-logic gate between distant quantum-network modules

Science ◽  
2021 ◽  
Vol 371 (6529) ◽  
pp. 614-617 ◽  
Author(s):  
Severin Daiss ◽  
Stefan Langenfeld ◽  
Stephan Welte ◽  
Emanuele Distante ◽  
Philip Thomas ◽  
...  
Keyword(s):  
Quantum Logic ◽  
Logic Gate ◽  
Logic Gates ◽  
Photon Detection ◽  
Quantum Networks ◽  
Quantum Logic Gate ◽  
Quantum Logic Gates ◽  
Network Modules ◽  
Nonlocal Quantum ◽  
Efficient Coupling

The big challenge in quantum computing is to realize scalable multi-qubit systems with cross-talk–free addressability and efficient coupling of arbitrarily selected qubits. Quantum networks promise a solution by integrating smaller qubit modules to a larger computing cluster. Such a distributed architecture, however, requires the capability to execute quantum-logic gates between distant qubits. Here we experimentally realize such a gate over a distance of 60 meters. We employ an ancillary photon that we successively reflect from two remote qubit modules, followed by a heralding photon detection, which triggers a final qubit rotation. We use the gate for remote entanglement creation of all four Bell states. Our nonlocal quantum-logic gate could be extended both to multiple qubits and many modules for a tailor-made multi-qubit computing register.

scholarly journals Design of Gates for Quantum Computation: The NOT Gate

1997 ◽  
Vol 11 (18) ◽  
pp. 2207-2215
Author(s):  
Dima Mozyrsky ◽  
Vladimir Privman ◽  
Steven P. Hotaling
Keyword(s):  
Quantum Logic ◽  
Logic Gate ◽  
Logic Gates ◽  
Time Dependent ◽  
Practical Realization ◽  
Quantum Logic Gate ◽  
Quantum Logic Gates ◽  
Gate Circuit ◽  
Spatially Extended ◽  
Analog Approach

We offer an alternative to the conventional network formulation of quantum computing. We advance the analog approach to quantum logic gate/circuit construction. As an illustration, we consider the spatially extended NOT gate as the first step in the development of this approach. We derive an explicit form of the interaction Hamiltonian corresponding to this gate and analyze its properties. We also discuss general extensions to the case of certain time-dependent interactions which may be useful for practical realization of quantum logic gates.

scholarly journals Introduction to Quantum Gates : Implementation of Single and Multiple Qubit Gates

2021 ◽  
pp. 385-392
Author(s):  
Ropa Roy ◽  
Asoke Nath
Keyword(s):  
Quantum Logic ◽  
Digital Circuits ◽  
Logic Gate ◽  
Logic Gates ◽  
Quantum Circuit ◽  
Quantum Gates ◽  
Quantum Logic Gate ◽  
Quantum Logic Gates ◽  
Classical Computing ◽  
Superposition States

A quantum gate or quantum logic gate is an elementary quantum circuit working on a small number of qubits. It means that quantum gates can grasp two primary feature of quantum mechanics that are entirely out of reach for classical gates : superposition and entanglement. In simpler words quantum gates are reversible. In classical computing sets of logic gates are connected to construct digital circuits. Similarly, quantum logic gates operates on input states that are generally in superposition states to compute the output. In this paper the authors will discuss in detail what is single and multiple qubit gates and scope and challenges in quantum gates.

Realizing an N-two-qubit quantum logic gate in a cavity QED with nearest qubit--qubit interaction

2016 ◽  
Vol 16 (5&6) ◽  
pp. 465-482
Author(s):  
Taoufik Said ◽  
Abdelhaq Chouikh ◽  
Karima Essammouni ◽  
Mohamed Bennai
Keyword(s):  
Quantum Logic ◽  
Cavity Qed ◽  
Logic Gate ◽  
Operation Time ◽  
Logic Gates ◽  
Initial State ◽  
Gate Operation ◽  
Quantum Logic Gates ◽  
Current State ◽  
Phase Gate

We propose an effective way for realizing a three quantum logic gates (NTCP gate, NTCP-NOT gate and NTQ-NOT gate) of one qubit simultaneously controlling N target qubits based on the qubit-qubit interaction. We use the superconducting qubits in a cavity QED driven by a strong microwave field. In our scheme, the operation time of these gates is independent of the number N of qubits involved in the gate operation. These gates are insensitive to the initial state of the cavity QED and can be used to produce an analogous CNOT gate simultaneously acting on N qubits. The quantum phase gate can be realized in a time (nanosecond-scale) much smaller than decoherence time and dephasing time (microsecond-scale) in cavity QED. Numerical simulation under the influence of the gate operations shows that the scheme could be achieved efficiently within current state-of-the-art technology.

scholarly journals Experimental realization of high-fidelity quantum logic gate between photons

2021 ◽  
Author(s):  
Shuai Shi ◽  
Biao Xu ◽  
Kuan Zhang ◽  
Gen-Sheng Ye ◽  
De-Sheng Xiang ◽  
...  
Keyword(s):  
Quantum Logic ◽  
Information Exchange ◽  
Logic Gate ◽  
Logic Gates ◽  
Building Blocks ◽  
High Fidelity ◽  
Single Photons ◽  
Long Distance ◽  
Experimental Realization ◽  
Quantum Logic Gate

Abstract Quantum logic gates with fidelity above fault-tolerant threshold are building blocks for scalable quantum technologies[1,2]. Compared to other types of qubits, photon is one of a kind due to its unparalleled advantages in long-distance quantum information exchange[3-5]. As a result, high-fidelity photonic quantum operations are not only indispensable for photonic quantum computation[6-8] but also critical for quantum network[2,9]. However, two-qubit photonic quantum logic gate with fidelity comparable to that of leading physical systems, i.e. 99.7% for superconducting circuits[10] and 99.9% for trapped ions[11], has not been achieved. A major limitation is the imperfection of single photons[12]. Here, we overcome this limitation by using high-quality single photons generated from Rydberg atoms as qubits for the interference-based gate protocol, and achieve a gate fidelity up to 99.84(3)%. Our work paves the way for scalable photonic quantum applications[13-15] based on near-optimal single-photon qubits and photon-photon gates.

scholarly journals ANALYSIS OF AN EXPERIMENTAL QUANTUM LOGIC GATE BY COMPLEMENTARY CLASSICAL OPERATIONS

2006 ◽  
Vol 21 (24) ◽  
pp. 1837-1850 ◽  
Author(s):  
HOLGER F. HOFMANN ◽  
RYO OKAMOTO ◽  
SHIGEKI TAKEUCHI
Keyword(s):  
Quantum Logic ◽  
Logic Gate ◽  
Bell State ◽  
Logic Gates ◽  
Basis Sets ◽  
Entanglement Generation ◽  
Quantum Logic Gates ◽  
State Discrimination ◽  
Logic Operations

Quantum logic gates can perform calculations much more efficiently than their classical counterparts. However, the level of control needed to obtain a reliable quantum operation is correspondingly higher. In order to evaluate the performance of experimental quantum gates, it is therefore necessary to identify the essential features that indicate quantum coherent operation. In this paper, we show that an efficient characterization of an experimental device can be obtained by investigating the classical logic operations on a pair of complementary basis sets. It is then possible to obtain reliable predictions about the quantum coherent operations of the gate such as entanglement generation and Bell state discrimination even without performing these operations directly.

scholarly journals Methodology for quantum logic gate construction

2000 ◽  
Vol 62 (5) ◽  
Author(s):  
Xinlan Zhou ◽  
Debbie W. Leung ◽  
Isaac L. Chuang
Keyword(s):  
Quantum Logic ◽  
Logic Gate ◽  
Quantum Logic Gate
Sign in / Sign up

Export Citation Format

Share Document