THE PARITY GATE: FROM QUANTUM NETWORKS TO ENTANGLEMENT GENERATION

2007 ◽  
Vol 05 (01n02) ◽  
pp. 3-7 ◽  
Author(s):  
RADU IONICIOIU
Keyword(s):  
Quantum Computing ◽  
Network Model ◽  
Quantum Network ◽  
Quantum Networks ◽  
Entanglement Generation ◽  
Simple Quantum ◽  
Parity Gate ◽  
Linear Elements ◽  
Quantum Network Model ◽  
Parity Measurement

It has been shown recently that parity measurement is an efficient entangler for fermions and hence is a universal resource for fermionic quantum computing with linear elements. In this article, we investigate several properties of the parity P-gate. We construct a simple quantum network model for the P-gate and derive gate identities for it. Finally, we examine entanglement generation using parity measurements.

scholarly journals Calculation of Electron Transport in Branched Semiconductor Nanostructures Using Quantum Network Model

2021 ◽  
Author(s):  
Davyd Tsurikov
Keyword(s):  
Electron Transport ◽  
Network Model ◽  
Semiconductor Nanostructures ◽  
Quantum Network ◽  
Electrical Currents ◽  
S Matrix ◽  
Quantum Network Model ◽  
Dimensional Electron Gas ◽  
Tunnel Effects ◽  
Network Junction

Abstract Electron transport in branched semiconductor nanostructures provides many possibilities for creating fundamentally new devices. We solve the problem of its calculation using a quantum network model. The proposed scheme consists of three computational parts: S-matrix of the network junction, S-matrix of the network in terms of its junctions’ S-matrices, electric currents through the network based on its S-matrix. To calculate the S-matrix of the network junction, we propose scattering boundary conditions in a clear integro-differential form. As an alternative, we also consider the Dirichlet-to-Neumann and Neumannto- Dirichlet map methods. To calculate the S-matrix of the network in terms of its junctions’ S-matrices, we obtain a network combining formula. We find electrical currents through the network in the framework of the Landauer– B¨uttiker formalism. Everywhere for calculations, we use extended scattering matrices, which allows taking into account correctly the contribution of tunnel effects between junctions. We demonstrate the proposed calculation scheme by modeling nanostructure based on two-dimensional electron gas. For this purpose we offer a model of a network formed by smooth junctions with one, two and three adjacent branches. We calculate the electrical properties of such a network (by the example of GaAs), formed by four junctions, depending on the temperature.

Efficient entanglement channel construction schemes for a theoretical quantum network model with d-level system

2011 ◽  
Vol 11 (6) ◽  
pp. 1715-1739 ◽  
Author(s):  
Ming-Ming Wang ◽  
Xiu-Bo Chen ◽  
Shou-Shan Luo ◽  
Yi-Xian Yang
Keyword(s):  
Network Model ◽  
Quantum Network ◽  
Level System ◽  
Quantum Network Model

scholarly journals Effective routing design for remote entanglement generation on quantum networks

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Changhao Li ◽  
Tianyi Li ◽  
Yi-Xiang Liu ◽  
Paola Cappellaro
Keyword(s):  
Scheduling Algorithm ◽  
Capacity Allocation ◽  
Quantum Network ◽  
Multiple Perspectives ◽  
Entanglement Purification ◽  
Quantum Networks ◽  
Entanglement Generation ◽  
The Road ◽  
Routing Scheme ◽  
Lattice Network

AbstractQuantum network is a promising platform for many ground-breaking applications that lie beyond the capability of its classical counterparts. Efficient entanglement generation on quantum networks with relatively limited resources such as quantum memories is essential to fully realize the network’s capabilities, the solution to which calls for delicate network design and is currently at the primitive stage. In this study we propose an effective routing scheme to enable automatic responses for multiple requests of entanglement generation between source-terminal stations on a quantum lattice network with finite edge capacities. Multiple connection paths are exploited for each connection request while entanglement fidelity is ensured for each path by performing entanglement purification. The routing scheme is highly modularized with a flexible nature, embedding quantum operations within the algorithmic workflow, whose performance is evaluated from multiple perspectives. In particular, three algorithms are proposed and compared for the scheduling of capacity allocation on the edges of quantum network. Embodying the ideas of proportional share and progressive filling that have been well-studied in classical routing problems, we design another scheduling algorithm, the propagatory update method, which in certain aspects overrides the two algorithms based on classical heuristics in scheduling performances. The general solution scheme paves the road for effective design of efficient routing and flow control protocols on applicational quantum networks.

scholarly journals Optimal teleportation via noisy quantum channels without additional qubit resources

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Dong-Gil Im ◽  
Chung-Hyun Lee ◽  
Yosep Kim ◽  
Hyunchul Nha ◽  
M. S. Kim ◽  
...  
Keyword(s):  
Quantum Computing ◽  
Quantum Teleportation ◽  
Quantum Communication ◽  
Quantum Noise ◽  
Single Copy ◽  
Entangled State ◽  
Quantum Network ◽  
Quantum Channels ◽  
Maximally Entangled State ◽  
Near Term

AbstractQuantum teleportation exemplifies how the transmission of quantum information starkly differs from that of classical information and serves as a key protocol for quantum communication and quantum computing. While an ideal teleportation protocol requires noiseless quantum channels to share a pure maximally entangled state, the reality is that shared entanglement is often severely degraded due to various decoherence mechanisms. Although the quantum noise induced by the decoherence is indeed a major obstacle to realizing a near-term quantum network or processor with a limited number of qubits, the methodologies considered thus far to address this issue are resource-intensive. Here, we demonstrate a protocol that allows optimal quantum teleportation via noisy quantum channels without additional qubit resources. By analyzing teleportation in the framework of generalized quantum measurement, we optimize the teleportation protocol for noisy quantum channels. In particular, we experimentally demonstrate that our protocol enables to teleport an unknown qubit even via a single copy of an entangled state under strong decoherence that would otherwise preclude any quantum operation. Our work provides a useful methodology for practically coping with decoherence with a limited number of qubits and paves the way for realizing noisy intermediate-scale quantum computing and quantum communication.

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