Correlated Electron Systems: Challenges and Future

Gabriel Kotliar

Rutgers University

What do we want from materials theory?

• New concepts , qualitative ideas

• Understanding, explanation of existent experiments, and predictions of new ones.

• Quantitative capabilities with predictive

power.

Materials Theory

a) System specific properties.

b) General principles, universal features.

• Qualitative insights, quantitative techniques, analytical and computational.

• Development of methods and algorithms, and study of system specific applications.

Balanced Approach

Mott transition and superexchange

Mott transition in V2O3 under pressure or chemical substitution on V-site

Phase Diagram k Organics

Mott transition in layered organic conductors S Lefebvre et al.

cond-mat/0004455, Phys. Rev. Lett. 85, 5420 (2000)

Failure of the Standard Model: NiSe2-xSxMiyasaka and

Takagi (2000)

Failure of the Standard Model: NiSe2-xSx

Miyasaka and Takagi (2000)

Failure of the Standard Model: NiSe2-xSxMiyasaka and

Takagi (2000)

Anomalous Resistivity and Mott transition Ni Se2-x Sx

Insights from DMFT: think in term of spectral functions (branch cuts) instead of well defined QP (poles )

Evolution of the Spectral Function

Double Occupancy vs U

• CDMFT Parcollet, Biroli GK

Pressure Driven Mott transition

Failure of the Standard Model: NiSe2-xSxMiyasaka and

Takagi (2000)

Transport in k organics

Ising critical endpoint! In V2O3

Mott transition in CDMFT

Strong frustration limit.

Anomalous transfer of spectral weight connected to the proximity to the Ising Mott endpoint (Kotliar Lange and Rozenberg Phys. Rev. Lett. 84, 5180 (2000)