arXiv subjects

A. V. Lugovskoi

Publications and source records attributed to A. V. Lugovskoi.

3 recordsLinked to original sources

arXiv2019

Strong electron-phonon coupling and its influence on the transport and optical properties of hole-doped single-layer InSe

We show that hole states in recently discovered single-layer InSe are strongly renormalized by the coupling with acoustic phonons. The coupling is enhanced significantly at moderate hole doping ($\sim$10$^{13}$ cm$^{-2}$) due to hexagonal warping of the Fermi surface. While the system remains dynamically stable, its electron-phonon spectral function exhibits sharp low-energy resonances, leading to the formation of satellite quasiparticle states near the Fermi energy. Such many-body renormalization is predicted to have two important consequences. First, it significantly suppresses charge carrier mobility reaching $\sim$1 cm$^2$V$^{-1}$s$^{-1}$ at $100$ K in a freestanding sample. Second, it gives rise to unusual temperature-dependent optical excitations in the midinfrared region. Relatively small charge carrier concentrations and realistic temperatures suggest that these excitations may be observed experimentally.

cond-mat.mtrl-sci↗

arXiv2019

Interplay between in-plane and flexural phonons in electronic transport of two-dimensional semiconductors

Out-of-plane vibrations are considered as the dominant factor limiting the intrinsic carrier mobility of suspended two-dimensional materials at low carrier concentrations. Anharmonic coupling between in-plane and flexural phonon modes is usually excluded from the consideration. Here we present a theory for the electron-phonon scattering, in which the anharmonic coupling between acoustic phonons is systematically taken into account. Our theory is applied to the typical group V two-dimensional semiconductors: hexagonal phosphorus, arsenic, and antimony. We find that the role of the flexural modes is essentially suppressed by their coupling with in-plane modes. At dopings lower than 10$^{12}$ cm$^{-2}$ the mobility reduction does not exceed 30\%, being almost independent of the concentration. Our findings suggest that compared to in-plane phonons, flexural phonons are considerably less important in the electronic transport of two-dimensional semiconductors, even at low carrier concentrations.

cond-mat.mtrl-sci↗

arXiv2019

Electron-phonon properties and superconductivity of doped antimonene

Antimonene is a recently discovered two-dimensional semiconductor with exceptional environmental stability, high carrier mobility, and strong spin-orbit interactions. In combination with electric field, the latter provides an additional degree of control over the materials' properties because of induced spin splitting. Here, we report on a computational study of electron-phonon coupling and superconductivity in $n$- and $p$-doped antimonene, where we pay a special attention on the effect of the perpendicular electric field. The range of accessible hole concentrations is significantly limited by the dynamical instability, associated with strong Fermi-surface nesting. At the same time, we find that in case of electron-doping antimonene remains stable and can be turned into a state with strong electron-phonon coupling, with the mass enhancement factor $λ$ of up to 2.3 at realistic charge carrier concentrations. In this regime, antimonene is expected to be a superconductor with the critical temperature of $\sim$16 K. Application of bias voltage leads to a considerable modification of the electronic structure, affecting the electron-phonon coupling in antimonene. While these effects are less obvious in case of electron-doping, field-effect in hole-doped antimonene results in a considerable variation of the critical temperature depending on bias voltage.

cond-mat.supr-con↗