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Valentin Voroshilov

Publications and source records attributed to Valentin Voroshilov.

7 recordsLinked to original sources
arXiv2018

The excitation energy spectrum for a system with electron pairs tunneling in a two-leg ladder has a doping depended gap

A new model with a new Hamiltonian is offered as the means for studying properties of a system of strongly correlated electrons. Consideration of the simplest possible situation, namely a system on non-interacting electrons in a two-leg ladder, leads to an expression for the excitation energy spectrum with no energy gap at the half-filling and with an energy gap away from the half filling.

physics.gen-ph↗
arXiv2014

The existence of a quantum phase transition in a Hubbard model on a square lattice

A novel canonical transformation is offered as the mean for studying properties of a system of strongly correlated electrons. As an example of the utility of the transformation, it is used to demonstrate the existence of a quantum phase transition in a Hubbard model on a square lattice. An Appendix presents two cases with a negative result.

cond-mat.str-el↗
arXiv2010

On a possibility of effective electron attraction without "a glue"

With the means of Schrodinger equation a two electron problem is considered. It is shown that electrons in a periodic potential might experience effective attraction without any mediating agents; which means electrons in HTSC might have effective attraction potential.

cond-mat.supr-con↗
arXiv2010

On Unconventional Electron Pairing In a Periodic Potential

On the assumption that two electrons with the same group velocity effectively attract each other a simple model Hamiltonian is proposed to question the existence of unconventional electron pairs formed by electrons in a strong periodic potential.

cond-mat.supr-con↗
arXiv2008

A simple model for describing a lattice with a double occupancy

A simple model is presented to investigate an impact of the double occupied sites on the ground state energy of a lattice. The model is seen as a useful tool to introduce undergraduate or graduate physics students to an array of a relatively simple mathematical apparatus and physical ideas which they can choose later for a deeper study. Instead of analyzing a system of electrons in a periodic potential, a system of sites having different energy states related to a number of extra electrons at a site is considered. The simplification is achieved by introducing operators for one-electron sites and two-electron sites as independent entities. A simple modeling function for the ground state of the system is constructed. Linear and quadratic lattices are considered. For a quadratic lattice the existence of a critical temperature is shown.

cond-mat.other↗