Ashutosh Singh — Page 4

arXiv2014

Wave packet dynamics in monolayer MoS$_2$ with and without a magnetic field

We study the dynamics of electrons in monolayer Molybdenum Disulfide (MoS$_2$), in the absence as well as presence of a transverse magnetic field. Considering the initial electronic wave function to be a Gaussian wave packet, we calculate the time dependent expectation value of position and velocity operators. In the absence of the magnetic field, the time dependent average values of position and velocity show damped oscillations dependent on the width of the wave packet. In the presence of a transverse magnetic field, the wave packet amplitude shows oscillatory behaviour over short timescales associated with classical cyclotron orbit, followed by the phenomena of spontaneous collapse and revival over larger timescales. We relate the timescales of these effects and our results can be useful for the interpretation of experiments with trapped ions.

cond-mat.mes-hall↗

arXiv2013

Multipath Approach for Reliability in Query Network based Overlaid Multicasting

In Application layer multicast (ALM) also called Overlay Multicast, multicast-related functionalities are moved to end-hosts. The key advantages, overlays offers, are flexibility, adaptability and ease of deployment [1]. Application layer multicast builds a peer-to-peer (P2P) overlay multicast tree topology consisting of end-to-end unicast connections between end-hosts. End users self organize themselves into logical overlay networks for efficient data delivery. Major concern in designing ALM protocol is how to build and maintain a topology, to route data efficiently and reliably. We propose here a scheme in which the topology is built incrementally while maintaining dual feeds of the media stream to any node from the source with minimum differential delay in receiving packets from both alternatives. We have made the assumption of availability of a P2P query search network. This enables building of multicast tree directly as an overlay. There is no need of maintaining an overlaid mesh and running multicast routing protocol to maintain a multicast tree in this mesh. Thus the scheme is much more simplified than in the earlier work on multicast overlay mesh creation and management and then creation and management of multicast trees using this mesh.

cs.NI↗