Decoherence from spin environment: Role of the Dzyaloshinsky-Moriya interaction

We study the time evolution of decoherence factor of two spin qubits and qutrits coupled to an $XY$ spin chain with Dzyaloshinsky-Moriya (DM) interaction environment. The dynamical process of the decoherence is numerically and analytically investigated. We find that the DM interaction can enhance slightly the decay of the decoherence factor in the weak-coupling region. However, in the strong-coupling region, the decoherence factor is very sensitive to the DM interaction.

Figure 1

Decoherence factor $\left|F\left(t\right)\right|$ as a function of $D$ and time $t$ for two qubits coupled to an Ising spin chain with DM interaction in the weak-coupling region under parameters $\lambda =1.0$, $\gamma =1.0$, $g=0.05$, and $L=801$. The unit of quantity $t$ is $\hslash /J$.

Figure 2

(Color online) Decoherence factor $\left|F\left(t\right)\right|$ as a function of time $t$ under different $D$ for two qubits coupled to a general $XY$ spin chain with DM interaction in the weak-coupling region under parameters $\lambda =1.0$, $g=0.05$, and $L=801$. (a) $\gamma =0.8$, (b) $\gamma =0.6$, and (c) $\gamma =0.4$. The unit of quantity $t$ is $\hslash /J$.

Figure 3

(Color online) Decoherence factor $\left|F\left(t\right)\right|$ as a function of the time $t$ for two central spin qubits coupled to an Ising spin chain under different $D$ in the strong-coupling region under parameters $\lambda =1.0$, $\gamma =1.0$, $g=500$, and $L=801$. (a) $D=0.0$, (b) $D=0.01$, and (c) $D=0.1$. The unit of quantity $t$ is $\hslash /J$.

Figure 4

Decoherence $\left|F_{12}\left(t\right)\right|$ as a function of $D$ and time $t$ for two qutrits coupled to an Ising spin chain with DM interaction in the weak-coupling region under the parameters $\lambda =1.0$, $\gamma =1.0$, $g=0.05$, and $L=801$. The unit of quantity $t$ is $\hslash /J$.

Figure 5

(Color online) Decoherence factors $\left|F_{12}\left(t\right)\right|$ as a function of the time $t$ for two qutrits coupled to an Ising spin chain under different $D$ in the strong-coupling region under the parameters $\lambda =1.0$, $\gamma =1.0$, $g=500$, and $L=201$. (a) $D=0.0$, (b) $D=1.0$, and (c) $D=2.0$. The unit of quantity $t$ is $\hslash /J$.