1) Oscillation Frequency -> Area of the Fermi surface
2) Can determine effective mass from temperature dependence
3) Map the Fermi Surface
What would the ground state of High Tc be if we kill superconductivity?
Checks:
A)Periodicity in 1/B strongly suggests Landau Quantization
B) Temperature Dependent Amplitude (Fermi-Dirac statistics obeyed)
Find extremely small pockets 40x smaller than band structure calculations.
Higher fields allow better resolution.
Warped cylinder leads to beating pattern. Fit data to 2 cylinders -> one normal + 1 warped.
Between YBCO and Tl2201 find 40x change in area of Fermi surface.
How to reconcile non-Fermi liquid at zero field with Quantum Oscillations
In Vortex liquid state when Q.O. seen.
Andre pushes us to stop asking questions at 9:36am... well done!
Electron pockets suggested by negative Hall or Hole pockets at the nodes. However size of pockets doesnt match doping.
Multiple pockets suggests large warping of on pocket... putting them at different locations.... holes in one place electrons in another...
Angular dependence also agrees with warping.
Warping suggests pockets at different regions since have different c-axis hopping parameters.
Implicit translational symmetry breaking leads to different pockets. But no long range order has been observed.
Zeeman splitting of the Fermi surface? Look at this with rotating magnetic field since orbital and spin have different angular dependence. Zeeman splitting should therefore lead to flip in phase of the oscillations, not seen.
Keimer et al claim to see inellastic bragg peaks in field. but not in the same doping.
Holes + electrons. Large part is hole part seen in Arpes. Area doesn't vary with doping but mass seems to diverge at lower doping.
Looks like MIT transition seen in resistivity goes to zero at doping where mass diverges.
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