Critical fermi surfaces and non-fermi liquid metals

1
Critical fermi surfaces and non-fermi liquid
metals

• T. Senthil (MIT)
• TS, Critical fermi surfaces and non-fermi
  liquid metals, PRB (to appear), arXiv
  08034009,
• Theory of a continuous Mott transition in two
  dimensions, arXiv 0804.1555
• Precursor TS, Annals of Physics, 06

2
Killing a Fermi surface
3
Example I Heavy electron critical points
Quantum critical point with striking non-fermi
liquid physics

• The Fermi surface may reconstruct dramatically
  across the quantum critical point due to loss of
  Kondo screening.

4
dHvA in CeRhIn5CeRhIn5
H. Shishido, R. Settai, H. Harima, Y. Onuki,
JPSJ 74, 1103 (2005)
5
Simpler example Mott transition of one band
systems
6
Possible experimental realization of a second
order Mott transition
7
Example III HiTc underlying normal metallic
ground state ?
8
Possible evolutions of Fermi surface with doping
at T 0
9
How might a Fermi surface disappear?
10
Electronic structure at criticality Critical
Fermi surface
11
Why a critical Fermi surface?
12
Evolution of single particle gap
13
Why a critical Fermi surface?Evolution of
momentum distribution
14
Killing a Fermi surface
15
Some obvious consequences/questions
16
Scaling phenomenology at a quantum critical point
with a critical Fermi surface?
17
Critical Fermi surface scaling for single
particle physics
18
New possibility angle dependent exponents
19
Leaving the critical point
20
Approach from the Fermi liquid
21
Specific heat singularity
22
Critical 2Kf surface
23
Implications of angle dependent exponents
24
Finite T crossovers
25
Tentative application to proposed hiTc critical
point
26
Calculational framework for critical Fermi
surfaces
27
Model calculations

• Only currently existing framework for
  calculations seems to be a slave particle theory.
  
• Examples
• Kondo breakdown model for Kondo lattices
• Theory of a continuous Mott transition in two
  dimensions

28
Model calculations for the Mott transition
29
Structure of critical theory
30
(No Transcript)
31
Critical Fermi surface at Mott criticality
32
Approach from Fermi liquid
33
Critical thermodynamics/transport
34
Universal resistivity jump
35
Crossover out of criticality Anderson is
different (from Higgs)
36
Finite T crossovers Marginal Fermi liquids
37
Summary-I

• At some metallic quantum critical points there
• will be an entire surface of critical fermionic
  modes
• a critical Fermi surface.
• Presence of critical fermi surface will change
  the scaling phenomena associated with universal
  critical singularities.
• Scaling hypotheses for single particle and
  thermodynamic quantities presence of critical
  2Kf surfaces,
• Possibility of angle dependent exponents with
  interesting consequences (eg metals with
  T-dependent Fermi arcs at intermediate
  temperature)

38
Summary-II

• Concrete theory of a continuous Mott transition
  in two dimensions
• demonstrate critical Fermi surface
• predict universal resistivity jump, emergence of
  marginal Fermi liquids
• Future Lots of challenges !