Hashimoto et al, Science 336, 1554 (2012)

BaFe2(As1-xPx)2: a QCP inside the superconducting dome?

• Is a peak in the penetration depth a signature of a QCP?

Levchenko et al, PRL 110, 177003 (2013)Chowdhury et al, PRL 111, 157004 (2013)

far from trivial…

• Why no peak in Ba(Fe1-xCox)2As2?

• Why a single quantum phase transition (compare with high-T)? very weak simultaneous 1st-order nematic-magnetic transition

Gordon et al, PRB 82, 054507 (2010)

Fernandes et al, PRL 111, 057001 (2013)