arXiv subjects

F. Dionigi

Publications and source records attributed to F. Dionigi.

2 recordsLinked to original sources

arXiv2011

Optical probing of correlation driven liquid-to-insulator transition in 2D electron gas

We study the quantum Hall liquid and the metal-insulator transition in a high mobility two dimensional electron gas, by means of photoluminescence and magneto-transport. In the integer and fractional regime at nu > 1/3, analyzing the emission energy dispersion we probe the magneto-Coulomb screening and the hidden symmetry of the electron liquid. In the fractional regime above above nu =1/3 the system undergoes the metal-to-insulator transition, and in the insulating phase the dispersion becomes linear with evidence of an increased renormalized mass.

cond-mat.str-el↗

arXiv2010

Plateau insulator transition in graphene

The quantum Hall effect in a single-layer graphene sample is studied in strong magnetic fields up to 28 T. Our measurements reveal the existence of a metal- insulator transition from filling factor $ν=-2$ to $ν=0$. The value of the universal scaling exponent is found to be $κ=0.57 $ in graphene and therefore in a truly two-dimensional system. This value of $κ$ is in agreement with the accepted universal value for the plateau-insulator transitions in standard quasi two-dimensional electron and hole gases.

cond-mat.mes-hall↗