Local Magnetic Susceptibility of the Positive Muon in the Quasi-One-Dimensional $S=1/2$ Antiferromagnet Dichlorobis (Pyridine) Copper (II)

We report muon spin rotation measurements of the local magnetic susceptibility around a positive muon in the paramagnetic state of the quasi-one-dimensional spin $1/2$ antiferromagnet dichlorobis (pyridine) copper (II). Signals from three distinct sites are resolved and have a temperature dependent frequency shift which is significantly different than the magnetic susceptibility. This difference is attributed to a muon induced perturbation of the spin $1/2$ chain. The obtained frequency shifts are compared with transfer matrix density–matrix renormalization-group numerical simulations.

Figure 1

Theoretical fit to the SQUID CPC data: The data were taken in an applied magnetic field of 0.5 T. The inset shows the chain of ${\mathrm{C}\mathrm{u}}^{2+}$ ions (adopted from Ref. 5).

Figure 2

The evolution of the FFT transforms with temperature in CPC.

Figure 3

Temperature dependence of the frequency shifts of the S1, S2, and S3 relaxing signals in CPC compared to the numerical calculations assuming two weak links of $J^{\prime }=0.34J$ for S1 and $J^{\prime }=0.36J$ for S2. For S3 a single weak link with $J^{\prime }=0.95J$ has been assumed.