Topology in quantum magnetism

Nyomtatóbarát változatNyomtatóbarát változat
PhD típus: 
Fizikai Tudományok Doktori Iskola
Év: 
2018/2019
Témavezető: 
Név: 
Penc Karlo
Email cím: 
penc.karlo@wigner.mta.hu
Intézet: 
Wigner Research Centre for Physics
Beosztás: 
Senior researcher
Tudományos fokozat: 
DSc
Konzulens: 
Név: 
Bordács Sándor
Email cím: 
bordacs.sandor@wigner.bme.hu
Intézet: 
BME Fizikai Intézet
Beosztás: 
Assistant Professor
Tudományos fokozat: 
PhD
Leírás: 

The ordered phases of magnetic materials are usually well understood within the framework of the mean-field approaches. However, competing interactions in quantum spin system can lead to entangled states which are beyond the traditional mean-field description. In such systems the order is often lost — they form the wide class of spin liquids. In other cases, the excitations above a trivial state have nontrivial topological properties, like a finite Chern number and edge states.

 
 In this PhD project we will search for the ground states and excitations in spin liquids and other entangled systems. What type of states can we describe with low dimensional tensor networks, how can we extend the AKLT type wave-functions to higher dimensional SU(2) spin models of localized electrons and SU(N) models of ultracold atoms. Can we excite non-abelian excitations? Can we contract magnetic systems where the second Chern number plays a role? How can we find experimental probes which could detect edge states?
 
This is a theoretical study, with analytical and numerical methods. 
 
Elvárások: 

Good knowledge of mathematical methods like group theory and linear algebra, of quantum mechanics and most importantly, enthusiasm and interest in pursuing a difficult, but rewarding problem.

 
Munkahely neve: 
Wigner Research Centre for Physics
Munkahely címe: 
1121 Budapest, Konkoly Thege Miklós út 29-33