Rectification current in overdamped ratchets can be easily controlled by applying two driving signals and tuning either their relative phase or their frequency ratio. The interplay of the two inputs generates intriguing transport mechanisms that can be implemented to optimize shuttling and separation of particles in a variety of physical and technological applications. PACS. 05.40.-a Fluctuatio...

We investigate two-dimensional melting of a colloidal system in the presence of a one-dimensional periodic substrate potential created by two interfering laser beams. We study the commensurability ratio p=sqrt[3]a/2d=2 with a the mean particle distance and d the period of the periodic potential. In contrast with the previously investigated case p=1, here we observe that melting of the locked-fl...

ABSTRACT This is a reply to the criticisms raised by William Jefferies (Jefferies, 2020) my article “Sraffa and Labour Theory of Value: note” (Araujo, 2019). In (2020) author has given great emphasis question physical commensurability between input output in Sraffa’s price model.

Via measurements of commensurability features near the Landau filling factor ν=1/2, we probe the shape of the Fermi contour for hole-flux composite fermions confined to a wide GaAs quantum well. The data reveal that the composite fermions are strongly influenced by the characteristics of the Landau level in which they are formed. In particular, their Fermi contour is warped when their Landau le...

We prove that fully residually free groups have the Howson property, that is the intersection of any two finitely generated subgroups in such a group is again finitely generated. We also establish some commensurability properties for finitely generated fully residually free groups which are similar to those of free groups. Finally we prove that for a finitely generated fully residually free gro...

We have measured the msgnetoresistance measurements of a 2D electron gas subjected to a periodic magnetic field created by the presence of type 11 superconducting stripes on the surface of the heterostructure. We observe oscillatory behaviour due to a commensurability effect between the cyclotron radius and the period of the magnetic field. The results can be understood in terms of a simple sem...

I study the conceptual framework of protein folding considering an exactly solvable model — the Rubik’s magic snake model. I discuss the mathematical representation of the model, the model Levinthal paradox, the non-unique compact folded structure, the function of the chain, the ground state energy, the commensurability between the folded structure and the potential sequence, the relationship b...