Name: Topological States of Matter: Insulators, Superconductors, and Quantum Hall Liquids
Start: 2012-07-30T08:00:00+02:00
End: 2012-08-25T18:00:00+02:00
Location: NORDITA

Monday, 30 July 2012

09:00 Light breakfast and registration
Light breakfast and registration
09:00 - 09:45

09:45 Opening remarks
Opening remarks
09:45 - 10:00
10:00 Topological Josephson junctions and solitons with non-Abelian statistics - Eytan Grosfeld (Ben-Gurion University)
Topological Josephson junctions and solitons with non-Abelian statistics
- Eytan Grosfeld (Ben-Gurion University)
10:00 - 11:00
Topological Josephson junctions and solitons with non- Abelian statistics Abstract: In recent years, chiral topological superconductors have been the subject of intensive study. These superconductors are characterized by the presence of charge-neutral Majorana edge states. Driven by prospects for applications in fault- tolerant quantum computation, Majorana fermions are ardently sought after. When a Josephson junction is formed between two topological superconductors, Josephson vortices through this junction carry a localized Majorana mode which affects their dynamics. In this talk I will discuss some of the properties of these Josephson vortices.
12:00 Lunch
Lunch
12:00 - 13:30
14:00 Transport properties of helical edge states - Patrik Recher (TU Braunschweig)
Transport properties of helical edge states
- Patrik Recher (TU Braunschweig)
14:00 - 15:00
15:00 Coffee break
Coffee break
15:00 - 15:30
Tuesday, 31 July 2012
10:00 Topological Surface States in Topological Insulators, Superconductors and Beyond - Zahid Hasan (Princeton University)
Topological Surface States in Topological Insulators, Superconductors and Beyond
- Zahid Hasan (Princeton University)
10:00 - 11:00
Bulk Topological Insulators are a new phase of electronic matter which realizes a non-quantum-Hall-like topological state in the bulk matter and unlike the quantum Hall liquids can be turned into superconductors. In this talk, I will first briefly review the basic theory and experimental probes that reveal topological order. I will then discuss experimental results that demonstrate the fundamental properties of topological insulators such as spin-momentum locking, non- trivial Berry’s phases, mirror Chern number, absence of backscattering or no U-turn rule, protection by time- reversal symmetry and the existence of room temperature topological order (at the level of M.Z.H and C.L. Kane, Rev. of Mod. Phys., 82, 3045 (2010)). I will then discuss the possible exotic roles of broken symmetry phases such as superconductivity and magnetism in doped topological insulators and their potential device applications in connection to our recent results as well as briefly outline the emerging research frontiers of the field as a whole. If time permits, I will discuss experimental progress in finding topological insulators beyond Kane-Mele Z2 paradigm.
12:00 Lunch
Lunch
12:00 - 13:30
14:00 Pfaffian versus anti-pfaffian at 5/2 and 3/8 - Jainendra Jain (Penn State University)
Pfaffian versus anti-pfaffian at 5/2 and 3/8
- Jainendra Jain (Penn State University)
14:00 - 15:00
15:00 Coffee break
Coffee break
15:00 - 15:30
Wednesday, 1 August 2012
10:00 Dirac fermions in HgTe - Laurens Molenkamp
Dirac fermions in HgTe
- Laurens Molenkamp
10:00 - 11:00
12:00 Lunch
Lunch
12:00 - 13:30
14:00 Bulk edge correlations and entanglement in a Maxwell-Chern-Simons model - Israel Klich (University of Virginia)
Bulk edge correlations and entanglement in a Maxwell-Chern-Simons model
- Israel Klich (University of Virginia)
14:00 - 15:00
15:00 Coffee break
Coffee break
15:00 - 15:30

17:00 Reception
Reception
17:00 - 19:00
Thursday, 2 August 2012
10:00 Mapping of parent Hamiltonians: from Abelian and non-Abelian quantum Hall states to exact models of critical spin chains - Martin Greiter (Karlsruher Institut für Technologie)
Mapping of parent Hamiltonians: from Abelian and non-Abelian quantum Hall states to exact models of critical spin chains
- Martin Greiter (Karlsruher Institut für Technologie)
10:00 - 11:00
We derive an exact model for a critical spin chain with arbitrary spin S, which includes the Haldane-Shastry model as the special case S=1/2. While spinons in the Haldane--Shastry model obey abelian half-fermi statistics, the spinons in the general model introduced here obey non-abelian statistics. This manifests itself through topological choices for the fractional momentum spacings. The general model is derived by mapping exact models of quantized Hall states onto spin chains. The lecture begins with pedagogical review of the Gutzwiller wave functions for S=1/2.
12:00 Lunch
Lunch
12:00 - 13:30
14:00 The two-channel Kondo fixed point in two dimensional topological superconductor - Ting Pong Choy (University of Leiden)
The two-channel Kondo fixed point in two dimensional topological superconductor
- Ting Pong Choy (University of Leiden)
14:00 - 15:00
15:00 Coffee break
Coffee break
15:00 - 15:30
Friday, 3 August 2012
10:00 Competition between d-wave and topological p-wave superconductivity in the doped Kitaev-Heisenberg model - Timo Hyart (Leipzig University)
Competition between d-wave and topological p-wave superconductivity in the doped Kitaev-Heisenberg model
- Timo Hyart (Leipzig University)
10:00 - 11:00
The competition between Kitaev and Heisenberg interactions away from half filling is studied for the doped Kitaev-Heisenberg $t$-$J_K$-$J_H$ model on a honeycomb lattice. While the isotropic Heisenberg coupling supports a time-reversal violating d-wave singlet state, we find that the Kitaev interaction favors a time-reversal invariant p-wave superconducting phase, which obeys the rotational symmetries of the microscopic model, and is robust for $J_H<J_K/2$. Within the p-wave superconducting phase, a critical chemical potential $|\mu|=\mu_c \approx t$ separates a topologically trivial phase for $|\mu|< \mu_c$ from a topologically non-trivial $Z_2$ time-reversal invariant spin-triplet phase for $|\mu|>\mu_c$. Because the topological p-wave superconductivity in the doped Kitaev model is considerably more robust to adding a Heisenberg exchange than the Kitaev spin liquid phase itself at zero doping, we expect that this type of physics might be observable in doped honeycomb iridates, in particular in Li$_2$IrO$_3$.
12:00 Lunch
Lunch
12:00 - 13:30

15:00 Coffee break
Coffee break
15:00 - 15:30
Saturday, 4 August 2012
Sunday, 5 August 2012