2018 CAP Congress / Congrès de l'ACP 2018

Confinement of magnetic monopole quasiparticles in a quantum spin ice (I)

11 Jun 2018, 16:15

30m

SUB 303 (cap.100) (Dalhousie University)

Invited Speaker / Conférencier(ère) invité(e) Condensed Matter and Materials Physics / Physique de la matière condensée et matériaux (DCMMP-DPMCM) M3-5 Magnetism (DCMMP) | Magnétisme (DPMCM)

Speaker

Prof. Christopher Ryan Wiebe

Description

We report direct spectroscopic evidence of correlations between monopoles in a quantum spin ice. A hierarchy of unequally spaced magnetic excitations has been observed via low energy inelastic neutron spectroscopy in Pr2Sn2O7, resembling the confinement of spin defects in low-dimensional quantum magnets.[1],[2] Using a simple linear potential model to fit the excitations, we have estimated the monopole pair creation energy, and calculated a lower bound for the tension between monopole-like quasiparticles. The linear potential model provides a natural explanation as to why detection of these correlations have been so elusive in the canonical dipolar spin ices. This is the first spectroscopic measurement of an effective “Dirac string” between magnetic monopoles.

References

[1] P. M. Sarte et al 2017 Journal of Physics: Condensed Matter Vol. 29, 45LT01.
[2] P. M. Sarte et al 2018, submitted to Physical Review Letters.