Essays about: "non-Hermitian Systems"

Found 4 essays containing the words non-Hermitian Systems.

1. 1. Dynamics at an exceptional point in an interacting quantum dot system

   University essay from Lunds universitet/Fasta tillståndets fysik; Lunds universitet/Fysiska institutionen

   Author : William Samuelson; [2022]
   Keywords : Physics and Astronomy;

   Abstract : A fundamental postulate of quantum mechanics is that the Hamiltonian of a closed system is Hermitian, guaranteeing real-valued energies and conserved probabilities throughout the evolution of the system. However, for quantum systems where there is dissipation and crosstalk with the environment, such as a system of quantum dots connected to an environment of metallic leads, the dynamics of the system is instead generated by a non-Hermitian Liouvillian superoperator. READ MORE

3. 2. A unified view of a family of soliton equations related to spin Calogero-Moser systems

   University essay from KTH/Fysik

   Author : Anton Ottosson; [2022]
   Keywords : Soliton equations; Solitons; Integrable systems; Spin Calogero-Moser systems; Exact solutions; Benjamin-Ono-type equations; Solitonekvationer; Solitoner; Integrerbara system; sCM-system; Exakta lösningar; Ekvationer av Benjamin-Ono-typ;

   Abstract : We study the interconnections between the spin Benjamin-Ono (sBO) and half-wave maps (HWM) equations, a pair of nonlinear partial integro-differential equations that have recently been found to permit multi-soliton solutions, where the time evolution of the constituent solitons can be described in terms of the well-known, completely integrable, spin Calogero-Moser (sCM) system. By considering a symmetry transformation of the sCM dynamics we are led to introduce a scale parameter into the sBO equation, yielding what we call the rescaled sBO (rsBO) equation, which has both the sBO and HWM equations as special cases. READ MORE

4. 3. Wannier Functions in non-Hermitian Systems

   University essay from KTH/Fysik

   Author : Alberto Zorzato; [2022]
   Keywords : Theoretical Physics; Condensed Matter Physics; non-Hermitian Systems; Wannier Functions;

   Abstract : The scope of this thesis is analyzing and characterizing certain gapless states in tight-binding non-Hermitian systems. We start by providing a pedagogical introduction to tight-binding theory, topological phases of matter, Wannier functions as real-space duals of Bloch functions and their properties, non-Hermitian systems and associated differences from standard Hermitian systems. READ MORE

5. 4. Finite-dimensional PT-symmetric Hamiltonians with an application to neutrino oscillations

   University essay from KTH/Skolan för teknikvetenskap (SCI)

   Author : Alexander Fagerlund; Chistopher Ekman; [2020]
   Keywords : ;

   Abstract : In this report, we first briefly summarize Hermitian quantum mechanics before moving on to the non-Hermitian case. We then review PT-symmetric quantum mechanics with a focus on finite-dimensional systems, and include a novel generalization of a perturbative calculation of the C-operator. READ MORE