About QUINST

Quantum mechanics is at the heart of our technology and economy - the laser and the transistor are quantum devices - but its full potential is far from being realized. Recent technological advances in optics, nanoscience and engineering allow experimentalists to create artificial structures or put microscopic and mesoscopic systems under new manipulable conditions in which quantum phenomena play a fundamental role.

Quantum technologies exploit these effects with practical purposes. The objective of Quantum Science is to discover, study, and control quantum efects at a fundamental level. These are two sides of a virtuous circle: new technologies lead to the discovery and study of new phenomena that will lead to new technologies.

Our group's aim is  to control and understand quantum phenomena in a multidisciplinary intersection of  Quantum Information, Quantum optics and cold atoms, Quantum Control, Spintronics, Quantum metrology, Atom interferometry, Superconducting qubits and Circuit QED and Foundations of Quantum Mechanics.

 

 

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Klaus Richter  (Univ. of Regensburg) (Seminar)

When end where

12/2012

Description

2011/06/24, Klaus Richter  (Univ. of Regensburg)
Place:  Sala de Seminarios del Departamento de Física Teórica e Historia de la Ciencia
Time: 12h
Title: Edge Phenomena in Graphene

Abstract
As distinct from the (smooth) confinement potential of semiconductor-based
lateral quantum dots, boundaries in graphene nanostructures, arising from
abrupt lattice termination, are (locally) composed of zigzag- or armchair-type
atomic arrangements. They for instance characterize nanoribbons, can give rise
to peculiar "edge states"  and usually vary along the edges of a graphene
quantum dot. Thereby the edges affect crucially the spectral and transport
properties of graphene nanostructures.

Here I develop a theoretical approach that is capable of handling such effects
in graphene quantum dots. I will first derive an exact expression for the
Green function of a mesoscopic graphene flake and then employ a semiclassical
path integral approach.
This allows for understanding peculiar phase-coherence effects in graphene
in terms of interference arising from the graphene pseudospin dynamics.