GIORGIO COLANGELO 'Can We Simultaneously Know Two Non-Commuting Observables?'

The uncertainty principle is at the core of quantum mechanics and sets ultimate limits of precise measurements. It is often thought that one of its consequences is that the precise simultaneous knowledge of non-commuting observables is impossible. In this talk I will show that in a scenario that naturally arises in atomic interferometry there is no sensing limit imposed by the uncertainty relation. Experimental data using a cold atomic ensemble demonstrate that simultaneous tracking of two non-commuting observables is possible with a measurement sensitivity far beyond the standard quantum limit.


JIL SCHWENDER 'Mass Sensing with Graphene and Carbon Nanotube Resonators'

In recent years nanoelectromechanical resonators made out of carbon nanotubes and graphene have attracted much attention thanks to their great potential for high resolution mass sensing as well as for the study of diffusion effects and phase transitions. A nanoelectromechanical resonator allows to extract the mass of molecules by measuring the shift in the resonance frequency when molecules get adsorbed onto the resonator. In this work we aim to achieve single molecule mass resolution with graphene nanomechanical resonator. The record of mass resolution achieved with a Carbon nanotube resonator is 1.7 yg. Up to know we managed to observe the adsorption of fullerene molecules onto a graphene resonator and we estimated its mass resolution with frequency stability measurements to be below 2.4 zg. With a single molecule on our resonator we expect to contribute to the understanding of the sources of frequency fluctuations of mechanical resonators.


PhD Seminar, June 17, 2016, 17:00. Seminar Room