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- Jan Kochanowski UniversityPL106 papers
- Yukhnovskii Institute for Condensed Matter Physics of the National Academy of Sciences of UkraineUA86 papers
- National Academy of Sciences of UkraineUA62 papers
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8 papers · 1 filter
Multidimensional quasi-exactly solvable potentials with two known eigenstates
V. M. Tkachuk, T. V. Fityo
A general approach for constructing multidimensional quasi-exactly solvable (QES) potentials with explicitly known eigenfunctions for two energy levels is proposed. Examples of new…
Square-lattice s=1/2 XY model and the Jordan-Wigner fermions: The ground-state and thermodynamic properties
Oleg Derzhko, Taras Verkholyak, Reimar Schmidt +1
Using the 2D Jordan-Wigner transformation we reformulate the square-lattice s=1/2 XY (XZ) model in terms of noninteracting spinless fermions and examine the ground-state and thermo…
Quantum phase transitions in alternating transverse Ising chains: Rigorous analytical and exact numerical results
Oleg Derzhko, Johannes Richter, Taras Krokhmalskii +1
We examine the ground state properties of the s=1/2 transverse Ising chain with regularly alternating bonds and fields using exact analytical results and exact numerical data for l…
Helium-4 Energy and Specific Heat in Superfluid and Normal Phase
A. A. Rovenchak
The calculation of the He4 energy and specific heat is carried out in a wide temperature range within the two-time temperature Green functions approach. The approximation improving…
A new class of non-Hermitian Hamiltonians with real spectra
T. V. Fityo
We construct a new class of non-Hermitian Hamiltonians with real spectra. The Hamiltonians possess one explicitly known eigenfunction.
Factorization and superpotential of the PT symmetric Hamiltonian
V. M. Tkachuk, T. V. Fityo
We study the factorization of the PT symmetric Hamiltonian. The general expression for the superpotential corresponding to the PT symmetric potential is obtained and explicit examp…