セミナー情報

兵庫県立大学フロンティア機能物質創製センター・オープンセミナー(第23回)
共催:量研機構・原子力機構・兵県大合同物性コロキウム(第99回)

23rd Open Seminar of Resear Center for New Functional Materials
99th QST-JAEA-UH Joint Condensed Matter Colloquium

日時: 平成29年3月21日(火) 14:30〜15:30
Date and time: 21st Mar. (Tue.) 14:30-15:30
場所: 兵庫県立大学理学部研究棟7階談話室(739号室)
Place: Lecture room 739 (7F), Faculty of Science, University of Hyogo
Title: Quantum Oscillations, Fermi Surface Reconstruction and Charge Density Waves in Cuprate Superconductors
Speaker: Timothy Ziman (ILL, France)
Abstract:

Magnetic quantum oscillations in high magnetic fields on high-temperature superconductors YBa2Cu3O6+δ were shown some years ago [1] to include a prominent low-frequency peak with two smaller neighbouring peaks. The separation and even the position of these three peaks is almost independent of doping. This pattern has been explained previously by rather special, exquisitely detailed, Fermi-surface reconstruction coming from Charge Density Waves. These Charge Density Waves have been observed by X-ray diffraction in both low, and recently, in high fields, using free electron Lasers and pulsed magnetic fields [2]. We propose [3] that the magnetic oscillations are of different origin, and their frequencies are related to the bilayer and inter-bilayer electron hopping rather than directly to the areas of tiny Fermi-surface pockets. Such so-called "slow oscillations" explain more naturally many features of the observations and allow us to estimate the inter-layer transfer integrals and in-plane Fermi momentum.

[1] Suchitra E. Sebastian and Cyril Proust, Annu. Rev. Condens. Matter Phys. 6, 411 (2015) and references therein.
[2] H. Jang et al, PNAS, 113, 14645(2016); arXiv:1607.05359.
[3] P. Grigoriev and T. Ziman arXiv:1606.03942.


世話人: 坂井徹 (兵庫県立大、量研機構SPring-8)
筒井健二(量研機構SPring-8)
中野博生(兵庫県立大)
Organizers: Toru Sakai(University of Hyogo, QST SPring-8)
Kenji Tsutsui(QST Pring-8)
Hiroki Nakano(University of Hyogo)