Spontaneous Disorder Near the Mott Transition on Frustrated Lattices

Explore the phenomenon of spontaneous disorder near the Mott transition on frustrated lattices in this 48-minute lecture by Pinaki Majumdar from the International Centre for Theoretical Sciences. Delve into the complex interplay between correlation and disorder in classical and quantum systems, focusing on the pyrochlore Hubbard model. Examine the effects of lattice geometry, frustration, and magnetic states on the Mott transition. Investigate experimental realizations in molybdates and analyze phase diagrams, magnetization, resistivity, and optical properties. Learn about effective models, coupling mechanisms, and strategies for understanding spontaneous disorder. Gain insights into tuning localization and compare theoretical predictions with experimental observations in this comprehensive exploration of Mott physics on frustrated lattices.

Correlation and Disorder in Classical and Quantum Systems
Spontaneous disorder near the Mott transition on frustrated lattices
Outline
Lattice geometry in the Mott transition..
Frustration?
There are several lattices with triangular motifs in 2D and 3D:
Real material? A snapshot..
The triangular and FCC support LRO, we focus on the pyrochlore..
The pyrochlore Mott transition..
How does the Mott transition occur on the pyrochlore Hubbard model?
Effective model at half filling:
What controls the magnetic state?
The correlated moments couple to the electrons via:
Results: average moment, residual resistivity and phase diagram
Finite temperature: DOS, resistivity..
Experiments, and a more complex model..
Moybdates R2Mo2O7 provide a realisation of pyrochlore Mott physics
Field driven insulator-metal transition in Gd2Mo2O7
What are the key issues?
R2Mo2O7: degrees of freedom Solovyev, 2003
Microscopic model
Simplify
We use the following strategy
"Spontaneous disorder" and its effects..
The qualitative physics:
How do these effects play out? phase diagrams..
Comparing with experiments i phase diagram, magnetisation..
Comparison ii resistivity, optical weight..
Focus on the T=0 state..
Tuning the degree of localisation: the JAF knob..
Thanks
Q&A