Critical fermi surfaces and nonfermi liquid metals

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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

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Killing a Fermi surface
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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.

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dHvA in CeRhIn5CeRhIn5
H. Shishido, R. Settai, H. Harima, Y. Onuki,
JPSJ 74, 1103 (2005)
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Simpler example Mott transition of one band
systems
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Example III HiTc underlying normal metallic
ground state ?
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Possible evolutions of Fermi surface with doping
at T 0
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How might a Fermi surface disappear?
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Electronic structure at criticality Critical
Fermi surface
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Why a critical Fermi surface?
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Evolution of single particle gap
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Killing a Fermi surface
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Some obvious consequences/questions
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Critical Fermi surface scaling for single
particle physics
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New possibility angle dependent exponents
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Leaving the critical point
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Approach from the Fermi liquid
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Specific heat singularity
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Critical 2Kf surface
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Implications of angle dependent exponents
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Finite T crossovers
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Tentative application to proposed hiTc critical
point
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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

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Model calculations for the Mott transition
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Slave rotor formulation of Mott transition
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(No Transcript)
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Critical Fermi surface at Mott criticality
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Approach from Fermi liquid
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Critical thermodynamics/transport
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Universal resistivity jump
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Crossover out of criticality Anderson is
different (from Higgs)
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Finite T crossovers Marginal Fermi liquids
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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)

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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
• Other results Stability of two dimensional
  Luttinger liquid phases of electrons (TS,
  unpublished)
• Future Lots of challenges !

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Why a critical Fermi surface?Evolution of
momentum distribution