arXiv subjects

Shalva M. Tsiklauri

Publications and source records attributed to Shalva M. Tsiklauri.

7 recordsLinked to original sources

arXiv2026

Intervalley Magnetotrions Tunable by Electric and Magnetic Fields in Buckled Two-Dimensional Materials

We develop a theoretical framework for intervalley magnetotrions in buckled two-dimensional materials, including silicene, germanene, and stanene, subjected to perpendicular electric and magnetic fields. Within the effective-mass approximation, the three-particle Schrödinger equation is formulated with the Rytova--Keldysh interaction potential and analyzed in the high-magnetic-field regime. We demonstrate that intervalley trions with equal electron and hole effective masses constitute an exceptional case for which the center-of-mass and internal motions separate exactly. The center-of-mass motion is governed by a two-dimensional harmonic-oscillator Hamiltonian, leading to quantized Landau states whose energies form electrically tunable Landau surfaces controlled by the magnetic field and the electric-field dependence of the carrier effective masses. The internal motion is investigated by solving the three-body Schrödinger equation within the framework of the hyperspherical harmonics method. Numerical calculations reveal that the trion binding energy increases monotonically with both magnetic and electric fields owing to the combined effects of magnetic confinement and electric-field-induced enhancement of the effective masses. The strongest binding is obtained for silicene, followed by stanene and germanene. The present work provides a unified description of both the collective center-of-mass motion and the internal dynamics of magnetotrions in Xene monolayers, demonstrating that both degrees of freedom can be independently manipulated by external electric and magnetic fields.

cond-mat.mes-hall↗

arXiv2024

Electric-field-tuned binding energies of trions in silicene, germanene, and stanene monolayers

We predict the formation of intravalley controllable trions in buckled two-dimensional (2D) materials such as silicene, germanene, and stanene monolayers in an external electric field. Performing a study within the framework of a nonrelativistic potential model using the method of hyperspherical harmonics (HH), the three-body Schrödinger equation is solved with the Rytova-Keldysh potential by expanding the wave functions of a trion in terms of the HH. Then, we numerically solve a resultant system of coupled differential equations. The ground state energies of intravalley trions controlled by the external electric field are presented. The dependencies of the binding energy (BE) of trions in silicene, germanene, and stanene as a function of the electric field are shown to be qualitatively similar. BEs of trions formed by $A$ and $B$ excitons have a non-negligible difference that increases slightly as the electric field increases. We demonstrate that trion BEs can be controlled by the external electric field.

cond-mat.mes-hall↗

arXiv2024

Trions in two-dimensional monolayers within the hyperspherical harmonics method. Application to transition metal dichalcogenides

We develop the theoretical formalism and study the formation of valley trions in transition metal dichalcogenide (TMDC) monolayers within the framework of a nonrelativistic potential model using the method of hyperspherical harmonics (HH) in four-dimensional space. We present the solution of the three-body Schrödinger equation with the Rytova-Keldysh (RK) potential by expanding the wave function of a trion in terms of the HH. The antisymmetrization of trions wave function is based on the electron and hole spin and valley indices. We consider a long-range approximation when the RK potential is approximated by the Coulomb potential and a short-range limit when this potential is approximated by the logarithmic potential. In a diagonal approximation, the coupled system of differential equations for the hyperradial functions is decoupled in both limits. Our approach yields the analytical solution for binding energy and wave function of trions in the diagonal approximation for these two limiting cases: the Coulomb and logarithmic potentials. We obtain exact analytical expressions for eigenvalues and eigenfunctions for negatively and positively charged trions. The corresponding energy eigenvalues can be considered as the lower and upper limits for the trions binding energies. The proposed theoretical approach can describe trions in TMDCs and address the energy difference between the binding energies of $X^{-}$ and $X^{+}$ in TMDC. Results of numerical calculations for the ground state energies with the RK potential are in good agreement with similar calculations and in reasonable agreement with experimental measurements of trion binding energies.

cond-mat.mes-hall↗

arXiv2017

Trion and Biexciton in Monolayer Transition Metal Dichalcogenides

We study the trion and biexciton in transition metal dichalcogenides monolayers within the framework of a nonrelativistic potential model using the method of hyperspherical harmonics (HH). We solve the three- and four-body Schrödinger equations with the Keldysh potential by expanding the wave functions of a trion and biexciton in terms of the antisymmetrized HH. Results of the calculations for the ground state energies are in good agreement with similar calculations for the Keldysh potential and in reasonable agreement with experimental measurements of trion and biexciton binding energies.

cond-mat.mes-hall↗

arXiv2016

Lightest Kaonic Nuclear Clusters

We present our study of kaonic three-body $\overset{\_}{K}NN$, $\overset{\_}{K}\overset{\_}{K}N$ and $KK\overset{\_}{K}$ and four-body $\overset{\_}{K}% NNN $, $\ $and $\overset{\_}{K}\overset{\_}{K}NN$ clusters within the framework of a potential model using the method of hyperspherical functions in momentum representation. To perform a numerical calculations for the bound state energy of the light kaonic system, we use a set of different potentials for the nucleon-nucleon and $\overset{\_}{K}N$ interactions, as well as for the kaon-kaon interaction. The calculations show that a quasibound state energy is not sensitive to the $NN$ interaction, and it shows very strong dependence on the $\overset{\_}{K}N$ potential. We also compare our results with those obtained using different theoretical approaches. The theoretical discrepancies in the binding energy and width for the lightest kaonic system related to the different $NN$ and $\overset{\_% }{K}N$ interactions are addressed.

nucl-th↗

arXiv2016

Benchmark for a quasi-bound state of the $\overset{\_}{K}pp$ system

We present three-body nonrelativistic calculations within the framework of a potential model for the kaonic cluster ${K^-}pp$ using two completely different methods: the method of hyperspherical harmonics in the momentum representation and the method of Faddeev equations in configuration space. To perform a numerical benchmark, different $NN$ and antikaon-nucleon interactions are applied. The results of the calculations for the ground state energy for the ${K^-}pp$ system obtained by both methods are in reasonable agreement. Although the ground state energy is not sensitive to the $NN$ interaction, it shows very strong dependence on the $\overset{\_}{K}N$ potential. We show that the dominant clustering of the ${K^-}pp$ system in the configuration $Λ(1405)+p$ allows us to calculate the binding energy to good accuracy within a simple cluster approach for the differential Faddeev equations. The theoretical discrepancies in the binding energy and width for the ${K^-}pp$ system related to the different $NN$ and $\overset{\_}{K}N$ interactions are addressed.

nucl-th↗

arXiv2011

Trions in coupled quantum wells and Wigner crystallization

We consider a restricted three body problem, where two interacted particles are located in two dimensional (2D) plane and interact with the third one located in the parallel spatially separated plane. The system of such type can be formed in the semiconductor coupled quantum wells, where the electrons (or holes) and direct excitons spatially separated in different parallel neighboring quantum wells that are sufficiently close to interact and form negative X- or positive X+ indirect trions. It is shown that at large interwell separations, when the interwell separation much greater than the exciton Bohr radius, this problem can be solved analytically using the cluster approach. Analytical results for the energy spectrum and the wave functions of the spatially indirect trion are obtained, their dependence on the interwell separations is analyzed and a conditional probability distribution is calculated. The formation of 2D Wigner crystal of trions at the low densities is predicted. It is shown that the critical density of the formation of the trion Wigner crystal is sufficiently greater than the critical density of the electron Wigner crystal.

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