What reconstructs the underdoped cuprate Fermi surface into small pockets? · revision history
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Superseded · first revision · record
- Title
- What reconstructs the underdoped cuprate Fermi surface into small pockets
- Plain
- In strong magnetic fields, underdoped YBa2Cu3O6+x shows quantum oscillations, field-periodic wiggles in resistance that reveal a small closed pocket of electrons, whereas at zero field the Fermi surface is a single large hole-like contour; some order must cut the large surface into pieces.
- Precise
- In YBa2Cu3O6+x ($p \sim 0.08\ \text{to}\ 0.15$) and HgBa2CuO4+d with superconductivity suppressed by $300\ \text{to}\ 900\,\mathrm{kG}$, quantum oscillations show a dominant frequency $F \sim 5.3\,\mathrm{MG}$ (about 2 percent of the Brillouin zone) and a negative Hall coefficient, indicating an electron pocket. Determine whether biaxial charge order with the measured $q_{\mathrm{CDW}}$ alone reconstructs the Fermi surface into this electron pocket, and where the additional hole pockets required by Luttinger counting are, or why they are absent. An answer is a reconstruction model reproducing F, its splitting and c-axis warping, the Hall sign and the carrier count, together with detection or exclusion of the predicted extra pockets.
- Settled by
- Quantum-oscillation detection, or a bound on the amplitude, of the predicted hole pockets in the same field and doping range, plus angle-resolved oscillation data matching the proposed reconstruction.
- Kind
- well-posed
- Answer type
- identification
- References
- (empty)
- Literature status
- partially-resolved
- Status note
- Reconstruction by charge order is the leading explanation of the electron pocket, but the hole pockets that such reconstructions predict have not been observed.
- Posed since
- 2007