Connecting High-Field Quantum Oscillations to Zero-Field Electron Spectral Functions in the Underdoped CupratesDecember 10, 2014
Reprinted by permission from Macmillan Publishers Ltd: Nature Communications ©2014
FIG. 1: Spectral functions in the presence of static and fluctuating order. [From: A. Allais, Debanjan Chowdhury & Subir Sachdev, "Connecting high-field quantum oscillations to zero-field electron spectral functions in the underdoped cuprates,"Nature Communications 5 (10 Dec 2014) doi:10.1038/ncomms6771]
The nature of the pseudogap regime of cuprate superconductors at low hole density remains unresolved. It has a number of seemingly distinct experimental signatures: a suppression of the paramagnetic spin susceptibility at high temperatures, low-energy electronic excitations that extend over arcs in the Brillouin zone, X-ray detection of charge-density wave order at intermediate temperatures and quantum oscillations at high magnetic fields and low temperatures.
Postdoc Andrea Allais, grad student Debanjan Chowdhury, and Prof. Subir Sachdev have published an article in Nature Communications which shows that a model of competing charge-density wave and superconducting orders provides a unified description of the intermediate and low-temperature regimes. The researchers describe treating quantum oscillations at high field beyond semiclassical approximations, finding clear and robust signatures of an electron pocket compatible with existing observations, and also predicting oscillations due to additional hole pockets. In the zero-field and intermediate temperature regime, they compute the electronic spectrum in the presence of thermally fluctuating charge-density and superconducting orders. The results are compatible with experimental trends.