Plasmon-phonon-polaritons in encapsulated phosphorene. (arXiv:2002.06614v1 [cond-mat.mes-hall])

2020-02-18T04:30:31+00:00February 18th, 2020|Categories: Publications|Tags: , , |

We consider a system consists of a doped monolayer phosphorene embedded between two hexagonal Boron Nitride (hBN) slabs along the heterostructure direction. The wavevector azimuthal angle dependence of the plasmon-polariton and plasmon-phonon-polariton modes of the hybrid system are calculated based on the random phase approximation at finite temperature. The collective modes illustrate strong anisotropy and strong coupling with phonon modes of the polar media and furthermore, the Landau damping occurs due to the intraband processes when plasmon enters intraband electron-hole continuum. Our numerical results show that the plasmon mode is highly confined to the surface along the zigzag direction. Owing to the strong electron-phonon interaction, the phonon dispersions in the Reststrahlen bands are also angle-dependent

Published : "arXiv Mesoscale and Nanoscale Physics".

Static adhesion hysteresis in elastic structures. (arXiv:2002.06717v1 [])

2020-02-18T02:29:50+00:00February 18th, 2020|Categories: Publications|Tags: , |

Adhesive interactions between elastic structures such as graphene sheets, carbon nanotubes, and microtubule axonemes exhibit hysteresis due to irrecoverable energy loss associated with bond breakage, even in static (rate-independent) experiments. Here we provide a simple theory that explains how bond breaking and elastic relaxation can drive static adhesion hysteresis over a debonding/rebonding cycle. We show that energy loss emerges from the coupling of a local event (bond breaking) to a nonlocal event (overall elastic relaxation), in a manner similar to the Lake-Thomas effect in polymers. Experiments with adherent microtubules allow us to quantify the hysteresis as a function of adhesion and elasticity parameters. Our model also helps guide the derivation of a self-consistent continuum boundary condition at the interface of adherent mechanical systems.

Published in: "arXiv Material Science".

Investigating the role of Cu foil orientation in the growth of large BN films synthesized by reactive RF magnetron sputtering. (arXiv:2002.06634v1 [cond-mat.mtrl-sci])

2020-02-18T02:29:49+00:00February 18th, 2020|Categories: Publications|Tags: , |

Two dimensional materials are an emerging class of materials which is transforming the present day research activity on a phenomenal scale. Hexagonal boron nitride is a wide band gap 2D material which is an excellent substrate for graphene based electronics. To achieve the full potential of hBN scalable and high yield growth procedures are required. Here, we demonstrate the synthesis of hBN by reactive R.F magnetron sputtering over copper foil. Copper foil preparation conditions determines the phase selectivity of BN films. Deposition of hBN on non-electropolished Cu foils with predominant (100) orientation resulted in growth of BN islands with mixed cubic and hexagonal BN phase. On electropolished Cu foils with high symmetry hexagonal (111) surface termination we get growth of continuous hexagonal BN films, while on Cu foils having (100) a