The transmission of quantum states in the anisotropic Heisenberg XXZ chain model with three-spin exchange interaction is studied. The average fidelity is used to evaluate the state transfer. It is found out that quantum communication can be enhanced by the anisotropic coupling and multiple spin interaction. Such spin model can reduce the time required for the perfect state transmission where the fidelity is unity. The maximally entangled Bell states can be generated and separated from the whole quantum systems.The transmission of quantum states in the anisotropic Heisenberg XXZ chain model with three-spin exchange interaction is studied. The average fidelity is used to evaluate the state transfer. It is found out that quantum communication can be enhanced by the anisotropic coupling and multiple spin interaction. Such spin model can reduce the time required for the perfect state transmission where the fidelity is unity. The maximally entangled Bell states can be generated and separated from the whole quantum systems.

arXiv:1208.1557Aug 8, 20120 citations

Pretty good quantum state transfer on isotropic and anisotropic Heisenberg spin chains using engineered couplings

Pablo Serra, Alejandro Ferrón, Omar Osenda

Using a global optimization algorithm, interchange coupling distributions are obtained for chains of quantum spins. The couplings give the magnitude of the interaction between the spins of the chain, both chains with Heisenberg Hamiltonian and XXZ type anisotropic Hamiltonian are considered. These couplings allow the chains to be used as channels to transmit quantum states according to the simplest transmission protocol. It is analyzed under which conditions it is possible to obtain very high transmission fidelities, both as a function of the arrival time and the maximum intensity allowed for the couplings. Special emphasis is placed on finding coupling sets that allow fast transmission, with short arrival times on the order of $N$ , where $N$ is the number of spins in the chain. The stability of the chains as transmission channels is analyzed also when the couplings are subject to static disorder. Finally it is shown that the transmission fidelity at different arrival times shows scaling properties.Using a global optimization algorithm, interchange coupling distributions are obtained for chains of quantum spins. The couplings give the magnitude of the interaction between the spins of the chain, both chains with Heisenberg Hamiltonian and XXZ type anisotropic Hamiltonian are considered. These couplings allow the chains to be used as channels to transmit quantum states according to the simplest transmission protocol. It is analyzed under which conditions it is possible to obtain very high transmission fidelities, both as a function of the arrival time and the maximum intensity allowed for the couplings. Special emphasis is placed on finding coupling sets that allow fast transmission, with short arrival times on the order of $N$, where $N$ is the number of spins in the chain. The stability of the chains as transmission channels is analyzed also when the couplings are subject to static disorder. Finally it is shown that the transmission fidelity at different arrival times shows scaling properties.

Jan 8, 20210 citations

Quantum communication in spin systems with long-range interactions

M. Avellino, Andrew J. Fisher, Sougato Bose

We calculate the fidelity of transmission of a single qubit between distant sites on semi-infinite and finite chains of spins coupled via the magnetic dipole interaction. We show that such systems often perform better than their Heisenberg nearest-neighbor coupled counterparts, and that fidelities closely approaching unity can be attained between the ends of finite chains without any special engineering of the system, although state transfer becomes slow in long chains. We discuss possible optimization methods, and find that, for any length, the best compromise between the quality and the speed of the communication is obtained in a nearly uniform chain of four spins.We calculate the fidelity of transmission of a single qubit between distant sites on semi-infinite and finite chains of spins coupled via the magnetic dipole interaction. We show that such systems often perform better than their Heisenberg nearest-neighbor coupled counterparts, and that fidelities closely approaching unity can be attained between the ends of finite chains without any special engineering of the system, although state transfer becomes slow in long chains. We discuss possible optimization methods, and find that, for any length, the best compromise between the quality and the speed of the communication is obtained in a nearly uniform chain of four spins.

arXiv:quant-ph/0603148Physical Review AJul 31, 200658 citations

ENHANCED TELEPORTATION THROUGH ANISOTROPIC HEISENBERG QUANTUM SPIN CHAINS

Xiang Hao, Shiqun Zhu

The teleportation via the channel of the thermal equilibrium states in anisotropic Heisenberg XYZ chains is analyzed. It is found that there are the critical temperatures below which entanglement teleportation can be realized. Entanglement teleportation is enhanced through anisotropic XYZ chains in contrast to the isotropic Heisenberg one. Anisotropic spin exchanges can increase these critical temperatures for the teleportation. Entanglement can be transferred in the ferromagnetic anisotropic Heisenberg chain while it cannot be done in the ferromagnetic isotropic one. The average fidelity of the teleportation can be improved in the antiferromagnetic chains.The teleportation via the channel of the thermal equilibrium states in anisotropic Heisenberg XYZ chains is analyzed. It is found that there are the critical temperatures below which entanglement teleportation can be realized. Entanglement teleportation is enhanced through anisotropic XYZ chains in contrast to the isotropic Heisenberg one. Anisotropic spin exchanges can increase these critical temperatures for the teleportation. Entanglement can be transferred in the ferromagnetic anisotropic Heisenberg chain while it cannot be done in the ferromagnetic isotropic one. The average fidelity of the teleportation can be improved in the antiferromagnetic chains.

Modern Physics Letters BJan 9, 20081 citation

Role of interference in quantum state transfer through spin chains

Andriy O. Lyakhov, Daniel Braun, Christoph Bruder

We examine the role that interference plays in quantum state transfer through several types of finite spin chains, including chains with isotropic Heisenberg interaction between nearest neighbors, chains with reduced coupling constants to the spins at the end of the chain, and chains with anisotropic coupling constants. We evaluate quantitatively both the interference corresponding to the propagation of the entire chain and the interference in the effective propagation of the first and last spins only, treating the rest of the chain as a black box. We show that perfect quantum state transfer is possible without quantum interference and provide evidence that the spin chains examined realize interference-free quantum state transfer to a good approximation.We examine the role that interference plays in quantum state transfer through several types of finite spin chains, including chains with isotropic Heisenberg interaction between nearest neighbors, chains with reduced coupling constants to the spins at the end of the chain, and chains with anisotropic coupling constants. We evaluate quantitatively both the interference corresponding to the propagation of the entire chain and the interference in the effective propagation of the first and last spins only, treating the rest of the chain as a black box. We show that perfect quantum state transfer is possible without quantum interference and provide evidence that the spin chains examined realize interference-free quantum state transfer to a good approximation.

arXiv:0705.3777Physical Review AAug 22, 200712 citations

Effect of Spin Dimensionality in the Fidelity of Spin Chain Quantum Communication

Art Graeson Briones Dumigpe, Eric A. Galapon

We consider an unmodulated linear spin chain composed of two qubits at the ends, which undergo nearest-neighbor interactions, with an arbitrary spin between them. The state of the qubit on one end is to be transmitted through the arbitrary spin and is received by the qubit on the other end with some fidelity. We look at the behavior of the average f idelity of state transfer through time as affected by the spin quantum number of the arbitrary spin in between the qubits. We f ind that the higher the spin quantum number becomes, the earlier it takes to achieve perfect or nearly perfect state transfer. Moreover, when the channel with arbitrary spin is subjected to environment interaction, results from the calculation of average fidelity suggest that increasing the spin quantum number of the channel provides a countermeasure to the effects of decoherence induced by the environment.We consider an unmodulated linear spin chain composed of two qubits at the ends, which undergo nearest-neighbor interactions, with an arbitrary spin between them. The state of the qubit on one end is to be transmitted through the arbitrary spin and is received by the qubit on the other end with some fidelity. We look at the behavior of the average f idelity of state transfer through time as affected by the spin quantum number of the arbitrary spin in between the qubits. We f ind that the higher the spin quantum number becomes, the earlier it takes to achieve perfect or nearly perfect state transfer. Moreover, when the channel with arbitrary spin is subjected to environment interaction, results from the calculation of average fidelity suggest that increasing the spin quantum number of the channel provides a countermeasure to the effects of decoherence induced by the environment.

Science DilimanJun 16, 20170 citations

N

, where

N

is the number of spins in the chain. The stability of the chains as transmission channels is analyzed also when the couplings are subject to static disorder. Finally it is shown that the transmission fidelity at different arrival times shows scaling properties.