Is the pseudogap endpoint p* a quantum critical point? · revision history

Revision 2

Accepted · core change · record

Changes against revision 1:

Title · changed
Revision 1: Is the pseudogap endpoint p* a quantum critical point
Revision 2: Is the pseudogap endpoint $p*$ a quantum critical point?
Plain
Near 19 percent hole doping the pseudogap vanishes, and there the electronic heat capacity peaks and resistance becomes linear in temperature, signs of a phase transition at zero temperature.
Precise · changed · core
Revision 1: With superconductivity suppressed by fields of several hundred kG, determine whether the endpoint $p*$ (0.19 to 0.23 depending on family) is a quantum critical point with an order parameter ($C/T \sim \operatorname{log}(1/T)$, Hall number change from $p\ \text{to}\ 1+p$) or a change of Fermi-surface topology without broken symmetry. An answer identifies the transition type and, if one exists, the order parameter whose fluctuations give the log divergence.
Revision 2: With superconductivity suppressed by fields of several hundred kG, determine whether the endpoint $p*$ (0.19 to 0.23 depending on family) is a quantum critical point with an order parameter ($C/T \sim \log(1/T)$, Hall number change from $p\ \text{to}\ 1+p$) or a change of Fermi-surface topology without broken symmetry. An answer identifies the transition type and, if one exists, the order parameter whose fluctuations give the log divergence.
Settled by
Detection of the order parameter (or proof of its absence) by a symmetry-sensitive probe in the same high-field regime where C/T diverges.
Kind
well-posed
Answer type
classification
References
(empty)
Literature status
contested
Status note
High-field specific heat (2019) found $C/T \sim \log(1/T)$ at $p*$ in Nd- and Eu-substituted La2-xSrxCuO4, but the associated order parameter is unidentified.
Posed since
(empty)

Decisions