Essays about: "Condensed matter theory"

Showing result 1 - 5 of 14 essays containing the words Condensed matter theory.

1. 1. Numerical Estimation of Critical Exponents in the 3D XY Model

   University essay from KTH/Fysik

   Author : Christoffer Beiming; [2023]
   Keywords : Theoretical physics; Condensed matter theory; Phase transitions; XY model; Critical exponents; Computational physics; Monte Carlo simulations; Teoretisk fysik; Kondenserade materiens teori; Fasövergångar; XY-modellen; Kritiska exponenter; Beräkningsfysik; Monte Carlo simulering;

   Abstract : The experimentally obtained value of the critical exponent ν is presently in significant disagreement with current theoretical predictions for the λ-universality class. We suggest two novel approaches of determining the exponents ν and η by utilizing the effects of finite size scaling. READ MORE

3. 2. Time-resolved x-ray diffraction study of longitudinal optical phonons in zincblende semiconductors

   University essay from Lunds universitet/Atomfysik; Lunds universitet/Fysiska institutionen

   Author : Lassi Linnala; [2022]
   Keywords : femtosecond THz radiation; ultrafast x-ray diffraction; pump-probe; longitudinal optical phonons; zincblende semiconductors; anharmonic decay; density functional perturbation theory; Physics and Astronomy;

   Abstract : Anharmonic decay of longitudinal optical (LO) phonons in zincblende semiconductors is not at present well characterized due to the polar and many-body nature of the problem. Femtosecond THz radiation offers a novel route to this study, as the interaction of this radiation is directly with the phonon lattice and these THz excited phonons do not have enough energy to excite electrons over the band gap. READ MORE

4. 3. Information Flow and Local Observables in Many Body Localized Systems

   University essay from KTH/Fysik

   Author : Daniel Niemi; [2022]
   Keywords : Theoretical physics; many body localization; localization; aubry-andré; aubry-andrei; condensed matter; quantum matter; Teroretisk fysik; mångpartikellokalisering; lokalisering; aubry-andré; aubry-andrei; kondenserad materia; kvantmateria;

   Abstract : Disordered quantum many-body systems exhibiting the many-body localization (MBL) phenomenon evade the fate of thermalization due to the existence of an extensively large set of quasi-local integrals of motion (l-bits). Due to the size of the Hilbert space of many-body systems, it is hard to compute the time evolution of many-body systems generally, which hinders our understanding of the MBL phenomenon. READ MORE

5. 4. Effects of power-law correlated disorder on a 3D XY model

   University essay from KTH/Fysik

   Author : Philip Broms; [2022]
   Keywords : Condensed matter physics; Ising model; XY model; Markov Chain Monte Carlo; Phase transition; Disorder; Theoretical physics; Wolff algorithm; Kondenserade materians teori; Isingmodell; XY-modell; Markovkedje-Monte Carlo-metoder; Teoretisk fysik; Oordning; Fasövergångar; Wolffalgoritmen;

   Abstract : This thesis investigates the effects of power-law correlated disorder on a three-dimensional XY model and the Weinrib-Halperin disorder relevance criterion’s pre-dictive ability. Ising models are used as a map to realise disorder couplings. READ MORE

6. 5. Higher Forms and Dimensional Hierarchy in Topological Condensed Matter

   University essay from KTH/Fysik

   Author : Yashar Honarmandi; [2022]
   Keywords : Theoretical physics; topological quantum matter; parametrized systems; Berry phase; higher Berry curvature; effective field theory; topological action; topological insulators; dimensional hierarchy; Teoretisk fysik; topologisk kvantmateria; parametriserade system; Berryfas; högre Berrykrökning; effektiv fältteori; topologisk verkan; topologiska isolatorer; dimensionshierarki;

   Abstract : This report discusses higher differential forms with applications in the study of topological phenomena. The integer quantum Hall effect is first discussed, demonstrating a connection between models on a lattice and quantum field theories bridged by a topological invariant, namely the Chern number. READ MORE