Postdoctoral Researcher Position - Suspended graphene and universality of 1/f noise

Employer
Aalto University
Location
Finland
Posted
September 07 2017
Discipline
Other
Position Type
Full Time
Organization Type
Academia

The NANO group at Aalto University's Department of Applied Physics (Helsinki, Finland) is looking for one postdoctoral researcher to join the Academy of Finland project “1/f noise”. This position is targeted in strengthening our capabilities in suspended graphene devices, which can be employed as sensors in various condensed matter systems.


DETAILS


1/f noise has been a mystery in physics for more than 50 years. Curiously, 1/f noise is observed in nature in various context, for example in brain signals, music, traffic, etc. The phenomenon is still not explained, not even in electrical devices in spite of several attempts. The 1/f noise mechanisms in solid state systems have recently become yet more important due to their impact on decoherence properties of qubit systems.


Problems dealing with the 1/f noise have traditionally been solved using empirical methods, which currently slows down the development of efficient quantum technology components based on entanglement and superposition. Our project will employ new ideas for making progress in understanding the generation of 1/f noise. Our hypothesis will go beyond the existing theories by including time dependent processes to the trap states created by lattice defects or impurities. It is clear that the distribution of the traps is not stationary. On the contrary, the distribution varies all the time depending on the particular impurities, the lattice, and of course the temperature.


In our work, we address all these issues both theoretically and experimentally. We test our theories using new two-dimensional materials. One of our main premises is that ultraclean suspended graphene forms an excellent low noise platform on which one can study the creation of noise fluctuators by controlled deposition of gas atoms on the graphene surface. By controlling and measuring the gas coverage nearly at single-atom level by mechanical resonance frequency, one can tune the dynamics of the deposited fluctuators in a precise fashion. By correlating the dynamics of adsorbed atoms with the changes in the 1/f noise, universal tests on the origin of 1/f noise can be performed.



This job comes from a partnership with Science Magazine and Euraxess