This is not the latest version of this item. The latest version can be found at: https://kops.unikonstanz.de/handle/123456789/41002.2
Type of Publication:  Working Paper/Technical Report 
Publication status:  Published 
URI (citable link):  http://nbnresolving.de/urn:nbn:de:bsz:35221vjne4m1did6x5 
Author:  Stadler, Pascal; Rastelli, Gianluca; Belzig, Wolfgang 
Year of publication:  2017 
ArXivID:  arXiv:1712.06361 
Summary: 
We investigate the effects of local vibrational excitations in the nonsymmetrized current noise S(ω) of a nanojunction. For this purpose, we analyze a simple model  the Holstein model  in which the junction is described by a single electronic level that is coupled to two metallic leads and to a single vibrational mode. Using the Keldysh Green's function technique, we calculate the nonsymmetrized current noise to the leading order in the chargevibration interaction. For the noise associated to the latter, we identify distinct terms corresponding to the meanfield noise and the vertex correction. The meanfield result can be further divided into an elastic correction to the noise and in an inelastic correction, the second one being related to energy exchange with the vibration. To illustrate the general behavior of the noise induced by the chargevibration interaction, we consider two limit cases. In the first case, we assume a strong coupling of the dot to the leads with an energyindependent transmission whereas in the second case we assume a weak tunneling coupling between the dot and the leads such that the transport occurs through a sharp resonant level. We find that the noise associated to the vibrationcharge interaction shows a complex pattern as a function of the frequency ω and of the transmission function or of the dot's energy level. Several transitions from enhancement to suppression of the noise occurs in different regions, which are determined, in particular, by the vibrational frequency. Remarkably, in the regime of an energyindependent transmission, the zero order elastic noise vanishes at perfect transmission and at positive frequency whereas the noise related to the chargevibration interaction remains finite enabling the analysis of the pure vibrationalinduced current noise.

Subject (DDC):  530 Physics 
Link to License:  Terms of use 
Bibliography of Konstanz:  Yes 
STADLER, Pascal, Gianluca RASTELLI, Wolfgang BELZIG, 2017. Finite frequency current noise in the Holstein model
@techreport{Stadler20171218T12:20:48ZFinit41002, title={Finite frequency current noise in the Holstein model}, year={2017}, author={Stadler, Pascal and Rastelli, Gianluca and Belzig, Wolfgang} }
Stadler_21vjne4m1did6x5.pdf  99 