"The pseudogap and the phase diagram of the cuprate superconductors"
When: September 25, 2007 (Tue), 03:30PM to 04:30PM
Hosted by:
Ophelia Tsui
Speaker: Phuan Ong, Princeton University
View the poster for this event.
This event is part of the Department Colloquia Series. Colloquia are at 3:30 in the Metcalf Science Center (SCI 107) Refreshments will be served at 3:15 in the 1st Floor Lounge
Two decades after its serendipitous discovery, high-temperature superconductivity remains a deep and wonderful mystery. Why do electrons pair to form a condensate at such high temperatures? In the phase diagram of the cuprates (plotting critical temperature Tc vs doping x), the most prominent feature is the pseudogap state which envelops the superconducting “dome” extending to temperatures much higher than Tc. I will describe recent Nernst and torque magnetometry experiments which have revealed a key feature of the pseudogap state. Cooper pairing, with concomitant vortex excitations, persists above Tc, deep into the pseudogap state. The pairing strength is much stronger, and onsets at higher temperatures, than previously suspected. The results emphasize the importance of phase coherence and rigidity in the phase diagram.