Control of Topology in Quantum Materials by Laser by Takashi Oka

DATES
Monday 20 Jun, 2016 - Wednesday 29 Jun, 2016
VENUE
Ramanujan Lecture Hall, ICTS Bangalore
APPLY
Understanding strongly interacting quantum many body systems is one of the major frontiers in present day physics. Condensed matter physics provides a wide panoply of systems where strong interaction between constituent particles play a dominant role; some examples of such systems are high temperature superconductors, spin-liquids, fractional quantum Hall systems, and ultracold atoms in the strong-coupling regime. Recent additions to this list include topological insulators/superconductors, transition metal oxides and their heterostructures. These materials have the added feature that they have strong spin-orbit coupling. The interplay of strong interactions and strong spin-orbit coupling is presently a frontier area of research in condensed matter physics.

This program aims to introduce graduate students and post-docs to different aspects of strongly interacting systems focusing on ideas which are recently animating the condensed matter community world-wide. The program will consist of a week-long pedagogical lectures from 20.06.2016 to 26.06.2016 on frontier areas, followed by three days of a discussion meeting from 27.06.2016 to 29.06.2016 on related topics, presenting and discussing the latest situation in these areas.

0:00:00 ICTS
0:00:58 Material Laser
0:02:33 1. Floquet topological insulator Multiband system (graphene) Circularly polarized Laser
0:04:00 2. Ultrafast spintronics Quantum magnets Circularly polarized Laser
0:05:04 3: Heterodyne Hall Effect: Quantization of a Snake State
0:06:31 Light matter coupling
0:07:29 Floquet theory basics (I/3) Use Fourier transformation
0:09:14 Floquet theory basics (2/4)
0:10:34 Floquet theory basics (3/3)
0:11:18 Floquet topological insulator
0:13:16 Non-equilibrium Kubo formula for photo-induced transport
0:17:05 Photo-induced Berry curvature (Chem density)
0:17:55 Ganichev's group (graphene) Esslinger's group (optical lattice) Laser induced Hall effect Haldane model
0:18:39 key idea Circularly polarized laser Control of Chirality
0:19:48 Microsoft Error Reporting
0:21:03 H(t) = Hspin + B(t) . S + E(t) .
0:21:57 Ultrafast spintronics (THz spin current generation)
0:22:04 Three examples
0:25:01 "Snake-states" in oscillating magnetic field
0:25:57 Closed orbit for special ratios r = w/2
0:27:52 Husimi transformation
0:29:04 Wave function
0:30:37 Floquet quasi-energy Spectrum
0:32:26 Many-body state and heterodyne Hall effect
0:34:16 How to realize? THz metamaterial
0:34:26 New states can be introduced by laser.