Special CEMS Colloquium


Prof. Zhi-Xun Shen (Stanford University)


17:00 - 18:00, April 21, 2014 (Monday)


Okochi-Hall, RIKEN


High Temperature Superconduc4vity – Insights from Einstein’s Electrons


It is now over 100 years since superconduc4vity was discovered and it took 45 years before a theory was formulated by Bardeen‐Cooper‐Schrieffer(BCS). Once understood, the impact has been felt far behind superconduc4vity itself. High‐temperature superconduc4vity in cupper oxides, with cri4cal temperature well above what was an4cipated by the BCS, was discovered 25 years ago and remains a major unsolved physics problem today.
The challenge of this problem is symbolized by a complex phase diagram consists of intertwined states with extreme proper4es in addi4on to unconven4onal superconduc4vity. None of them can be described by conven4onal theory, thus compounding the difficulty to understand high‐temperature superconduc4vity itself as these states are different manifesta4ons of the same underlying physical system, making an integrated understanding a necessity.
Angle‐resolved photoemission spectroscopy (ARPES), derived from Einstein’s formula4on of photoelectric effect, has emerged as a leading experimental tool to push the fron4er of this important field of modern physics. Over the last two decades, the improved resolu4on and carefully matched experiments have been the keys to turn this technique into a sophis4cated many‐body physics tool. As a result, ARPES played a cri4cal role in seWng the intellectual agenda by tes4ng new ideas and discovering surprises. This talk focuses on the insights we have gained on the rich phase diagram of the copper oxide superconductors – a pre‐requisite for a complete understanding of high temperature superconduc4vity./p>