Quantum Entanglement and Teleportation of Magnons in Coupled Spin Chains

Abstract

This study explores how entanglement and quantum teleportation of magnons can be achieved in coupled spin chain systems. By utilizing different magnetic configurations, we show that parallel spin chains function like magnonic beam splitters, whereas anti-parallel chains produce two-magnon squeezing and strong entanglement. Combining these components, we design magnonic circuits capable of continuous-variable quantum entanglement and teleportation, supported by quantum Langevin simulations.

Figures (4)

• Figure 1: The realization of beam splitter and two-mode squeezer for magnons using parallel and anti-parallel configurations.
• Figure 2: (a) The quantum circuitry for entanglement generation (in AP region) and conversion to single-mode squeezing (in P region). (b) The temporal-spatial propagation of cross-chain entanglement. (c) The temporal-spatial propagation of the single-mode squeezing (in chain-$A$). (d) The magnitude of the entanglement evaluated around site-10 as function of coupling strength $J'$ and duration $\tau_{\text{AP}}$ in AP. (e) The residue entanglement evaluated around site-45 as a function of $J'$ and $\tau_{\text{P}}$.
• Figure 3: (a) The quantum circuitry for magnon teleportation with three spin chains. (b) The entanglement between chain-A and -B. (c) The entanglement between chain-C and -B. (d) The amplitudes of coherent states on chain-A and -C. (e) The teleportation fidelity as function of the phases realized in the AP and P region.
• Figure 4: The total inter-chain entanglement of a double chain model in Fig. \ref{['fig:doublechain']}, $E_{\text{N,total}}=E_{\text{N}}[V]$, is calculated as a function of time at different temperatures. The damping rate is fixed at $\gamma = 10^{-4}$. The P coupling region is switched off here. The red dashed line is $65mK$, correlated to a single magnon excitation in YIG.