Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:quant-ph/0702029 · Physical Review A

Quantum communication via a continuously monitored dual spin chain

Kosuke Shizume, Kurt A. Jacobs, Daniel Klaus Burgarth, Sougato Bose

Published Jun 21, 2007• 17 citations
arXivHTMLPDF

Abstract

We analyze a recent protocol for the transmission of quantum states via a dual spin chain [Burgarth and Bose, Phys. Rev. A 71, 052315 (2005)] under the constraint that the receiver's measurement strength is finite. That is, we consider the channel where the ideal, instantaneous, and complete von Neumann measurements are replaced with a more realistic continuous measurement. We show that for optimal performance the measurement strength must be ``tuned'' to the channel spin-spin coupling, and once this is done, one is able to achieve a similar transmission rate to that obtained with ideal measurements. The spin chain protocol thus remains effective under measurement constraints.

DOI
10.1103/physreva.75.062328

Related papers

Simultaneous multiple-user quantum communication across a spin-chain channel

Rozhin Yousefjani, Abolfazl Bayat

The time evolution of spin chains has been extensively studied for transferring quantum states between different registers of a quantum computer. Nonetheless, in most of these protocols only one sender-receiver pair can share the channel at each time. This significantly limits the rate of communication in a network of many users because they can only communicate through their common data-bus sequentially and not all at the same time. Here, we propose a protocol in which multiple users can share a spin chain channel simultaneously without having crosstalk between different parties. This is achieved by properly tuning the local parameters of the Hamiltonian to mediate an effective interaction between each pair of users via a distinct set of energy eigenstates of the system. We introduce three strategies with different levels of Hamiltonian tuning; each might be suitable for a different physical platform. All the three strategies provide very high transmission fidelities with vanishingly small crosstalk. The protocol is robust against various imperfections and we specifically show that our protocol can be experimentally realized on currently available superconducting quantum simulators.

arXiv:1912.03475•Physical Review A•Jul 15, 2020•21 citations

Spin-Chains as Quantum Channels for Qubit-State Transfer

Giulia Gualdi, Irene Marzoli, Paolo Tombesi

In this paper, we provide a simple strategy to optimize the performances of a spin chain as a quantum channel for state transfer.We investigate the most general conditions under which a long range interacting chain achieves the highest fidelity and the shortest transfer time. In this respect, we show that the symmetry of the spin chain plys a key role to identify the ideal system, which involves sender and receiver only, and provide numerical evidence. However, the two-spin ideal chain is unpractical due to the decrease of the coupling strength with distance. Therefore we show how to design a spin chain, which nearly approaches the optimal behaviour, while keeping the interaction strength still reasonably high.

International Conference on Quantum, Nano and Micro Technologies (ICQNM)•Feb 1, 2009•0 citations

Arbitrarily perfect quantum communication using unmodulated spin chains, a collaborative approach

B Vaucher, Daniel Klaus Burgarth, Sougato Bose

We shall consider a quantum communication channel constituted by two open spin chains with nearest neighbour interactions and fixed coupling strengths, connected to several users. Assuming that the users of this quantum data bus can apply simple gates on sites of the chain that they are connected to, we will see that it is possible to gain information on the position of the qubit during the transmission, and to use this information to accelerate the communication process. We will also see that performing frequent measurements on the system affects the dynamics of propagation of quantum information in an interesting way.

Journal of Optics B Quantum and Semiclassical Optics•Sep 21, 2005•6 citations

Conclusive and arbitrarily perfect quantum-state transfer using parallel spin-chain channels

Daniel Klaus Burgarth, Sougato Bose

We suggest a protocol for perfect quantum communication through spin-chain channels. By combining a dual-rail encoding with measurements only at the receiving end, we can get conclusively perfect state transfer, whose probability of success can be made arbitrarily close to unity. As an example of such an amplitude-delaying channel, we show how two parallel Heisenberg spin chains can be used as quantum wires. Perfect state transfer with a probability of failure lower than $P$ in a Heisenberg chain of $N$ spin-$\frac{1}{2}$ particles can be achieved in a timescale of the order of $(0.33\ensuremath{\hbar}∕J){N}^{1.7}\ensuremath{\mid}\mathrm{ln}\phantom{\rule{0.2em}{0ex}}P\ensuremath{\mid}$. We demonstrate that our scheme is more robust to decoherence and nonoptimal timing than any scheme using single spin chains.

arXiv:quant-ph/0406112•Physical Review A•May 13, 2005•247 citations

Conclusive and arbitrarily perfect quantum state transfer using amplitude delaying spin chain channels

Daniel Klaus Burgarth, Sougato Bose

We suggest a protocol for the transfer of quantum information in spin chain channels with a finite recurrence time. By combining a dual-rail encoding with certain measurements at the receiving end, we can get arbitrarily perfect state transfer, i.e. by performing sufficiently many measurements at the receiving end, we can make the probability of perfect state transfer arbitrary close to unity. As an example of such an amplitude delaying channel, we show how two parallel Heisenberg spin chains can be used as quantum wires in solid state quantum computers. Perfect state transfer with a probability of failure lower than delta in a Heisenberg chain of N spin-1/2 particles can be achieved in a timescale of the order of N^(7/3)*|ln(delta)|. Furthermore, the same scheme can be implemented using a single SU(n) chain which is realizable in quantum dot arrays.

•Jun 15, 2004•0 citations

Measurement-assisted quantum communication in spin channels with dephasing

Abolfazl Bayat, Yasser Omar

We propose a protocol for countering the effects of dephasing in quantum state transfer over a noisy spin channel weakly coupled to the sender and receiver qubits. Our protocol, based on performing regular global measurements on the channel, significantly suppresses the nocuous environmental effects and offers much higher fidelities than the traditional no-measurement approach. Our proposal can also operate as a robust two-qubit entangling gate over distant spins. Our scheme counters any source of dephasing, including those for which the well established dynamical decoupling approach fails. Our protocol is probabilistic, given the intrinsic randomness in quantum measurements, but its success probability can be maximized by adequately tuning the rate of the measurements.

arXiv:1502.03468•New Journal of Physics•Oct 19, 2015•21 citations
We analyze a recent protocol for the transmission of quantum states via a dual spin chain [Burgarth and Bose, Phys. Rev. A 71, 052315 (2005)] under the constraint that the receiver's measurement strength is finite. That is, we consider the channel where the ideal, instantaneous, and complete von Neumann measurements are replaced with a more realistic continuous measurement. We show that for optimal performance the measurement strength must be ``tuned'' to the channel spin-spin coupling, and once this is done, one is able to achieve a similar transmission rate to that obtained with ideal measurements. The spin chain protocol thus remains effective under measurement constraints.
The time evolution of spin chains has been extensively studied for transferring quantum states between different registers of a quantum computer. Nonetheless, in most of these protocols only one sender-receiver pair can share the channel at each time. This significantly limits the rate of communication in a network of many users because they can only communicate through their common data-bus sequentially and not all at the same time. Here, we propose a protocol in which multiple users can share a spin chain channel simultaneously without having crosstalk between different parties. This is achieved by properly tuning the local parameters of the Hamiltonian to mediate an effective interaction between each pair of users via a distinct set of energy eigenstates of the system. We introduce three strategies with different levels of Hamiltonian tuning; each might be suitable for a different physical platform. All the three strategies provide very high transmission fidelities with vanishingly small crosstalk. The protocol is robust against various imperfections and we specifically show that our protocol can be experimentally realized on currently available superconducting quantum simulators.
In this paper, we provide a simple strategy to optimize the performances of a spin chain as a quantum channel for state transfer.We investigate the most general conditions under which a long range interacting chain achieves the highest fidelity and the shortest transfer time. In this respect, we show that the symmetry of the spin chain plys a key role to identify the ideal system, which involves sender and receiver only, and provide numerical evidence. However, the two-spin ideal chain is unpractical due to the decrease of the coupling strength with distance. Therefore we show how to design a spin chain, which nearly approaches the optimal behaviour, while keeping the interaction strength still reasonably high.
We shall consider a quantum communication channel constituted by two open spin chains with nearest neighbour interactions and fixed coupling strengths, connected to several users. Assuming that the users of this quantum data bus can apply simple gates on sites of the chain that they are connected to, we will see that it is possible to gain information on the position of the qubit during the transmission, and to use this information to accelerate the communication process. We will also see that performing frequent measurements on the system affects the dynamics of propagation of quantum information in an interesting way.
We suggest a protocol for perfect quantum communication through spin-chain channels. By combining a dual-rail encoding with measurements only at the receiving end, we can get conclusively perfect state transfer, whose probability of success can be made arbitrarily close to unity. As an example of such an amplitude-delaying channel, we show how two parallel Heisenberg spin chains can be used as quantum wires. Perfect state transfer with a probability of failure lower than PPP in a Heisenberg chain of NNN spin-12\frac{1}{2}21​ particles can be achieved in a timescale of the order of $(0.33\ensuremath{\hbar}∕J){N}^{1.7}\ensuremath{\mid}\mathrm{ln}\phantom{\rule{0.2em}{0ex}}P\ensuremath{\mid}$. We demonstrate that our scheme is more robust to decoherence and nonoptimal timing than any scheme using single spin chains.
We suggest a protocol for the transfer of quantum information in spin chain channels with a finite recurrence time. By combining a dual-rail encoding with certain measurements at the receiving end, we can get arbitrarily perfect state transfer, i.e. by performing sufficiently many measurements at the receiving end, we can make the probability of perfect state transfer arbitrary close to unity. As an example of such an amplitude delaying channel, we show how two parallel Heisenberg spin chains can be used as quantum wires in solid state quantum computers. Perfect state transfer with a probability of failure lower than delta in a Heisenberg chain of N spin-1/2 particles can be achieved in a timescale of the order of N^(7/3)*|ln(delta)|. Furthermore, the same scheme can be implemented using a single SU(n) chain which is realizable in quantum dot arrays.
We propose a protocol for countering the effects of dephasing in quantum state transfer over a noisy spin channel weakly coupled to the sender and receiver qubits. Our protocol, based on performing regular global measurements on the channel, significantly suppresses the nocuous environmental effects and offers much higher fidelities than the traditional no-measurement approach. Our proposal can also operate as a robust two-qubit entangling gate over distant spins. Our scheme counters any source of dephasing, including those for which the well established dynamical decoupling approach fails. Our protocol is probabilistic, given the intrinsic randomness in quantum measurements, but its success probability can be maximized by adequately tuning the rate of the measurements.