New Macroscopic Windows into Spin Ice: From Emergent Monopoles to Quadrupolar Fluctuations

Seminar Research
On  June 4, 2026
Nan Tang (University of Augsburg) will give a Quantum Materials Seminar on Thursday the 4th of June at 2PM in the Neel Institute Room K223 Remy Lemaire.
Spin ice, a representative class of frustrated magnets, provides a rich platform for exploring phenomena such as fractionalized excitations and multipolar degrees of freedom, which remain difficult to access using conventional magnetic probes. In this seminar, I will show how thermodynamic measurements, especially elastic probes, together with spintronics technique (in particular the spin Seebeck effect), can serve as practical detectors of these degrees of freedom.

I will develop this theme via two studies in the pyrochlore oxides Pr2​Zr2​O7​ and Dy2​Ti2​O7​, known as spin ices. First, I will show how bulk thermodynamic measurements, centered around elastic probes, can diagnose quantum spin ice physics in Pr2​Zr2​O7​ [1]. Second, I will discuss how transport-sensitive measurements in an insulator—through the spin Seebeck effect—can access the dynamics of emergent magnetic monopoles in the classical spin ice Dy2​Ti2​O7​ [2]. Together, these two studies demonstrate how lattice-based probes and spintronic tools can be brought to bear on frustrated magnets, providing new routes to detect low-energy degrees of freedom.

In this way, precision thermodynamics and modern transport-sensitive techniques can reveal new physics even in long-studied frustrated magnets, enabling direct comparison with theory through sharp macroscopic signatures.

[1] N. Tang et al., Nat. Phys. 19, 92-98 (2023).
[2] N. Tang et al., preprint, arXiv.2509.18422 (2025).
 
Published on  May 29, 2026
Updated on  May 29, 2026