Density-matrix spectra for two-dimensional quantum systems

Open Quantum Systems: Density Matrix Formalism and Applications

Deformed oscillator algebras for two-dimensional quantum superintegrable systems.

Quantum superintegrable systems in two dimensions are obtained from their classical counterparts, the quantum integrals of motion being obtained from the corresponding classical integrals by a symmetrization procedure. For each quantum superintegrable system a deformed oscillator algebra, characterized by a structure function specific for each system, is constructed, the generators of the algeb...

Self-similar solutions‎ ‎of the Riemann problem for two-dimensional systems of conservation‎ ‎laws

In this paper, a new approach is applied to study the self-similar solutions of 2×2 systems of nonlinear hyperbolic conservation laws. A notion of characteristic directions is introduced and then used to construct local and smooth solutions of the associated Riemann problem

Two-Dimensional Quantum Gravity

We show equivalence between the standard weak coupling regime c > 25 of the the two-dimensional quantum gravity and regime h < 1/2 of the original geometric approach of Polyakov [1, 2], developed in [3, 4, 5]. 1 In this letter I shall demonstrate the equivalence of two approaches to the twodimensional quantum gravity. The first approach, called geometric, goes back to Polyakov’s original discov...

Two-quantum many-body coherences in two-dimensional fourier-transform spectra of exciton resonances in semiconductor quantum wells.

We present experimental coherent two-dimensional Fourier-transform spectra of Wannier exciton resonances in semiconductor quantum wells generated by a pulse sequence that isolates two-quantum coherences. By measuring the real part of the signals, we determine that the spectra are dominated by two-quantum coherences due to mean-field many-body interactions, rather than bound biexcitons. Simulati...