Recurrent Quantum Scars in a Mesoscopic Graphene Ring.
When coherent charge carriers cross micron-scale cavities, their dynamics can be governed by a few resonant states, also called "quantum scars", determined by the cavity geometry. Quantum scars can be described using theoretical tools but have also been directly imaged in the case of high-quality semiconductor cavities as well as in disordered graphene devices, thanks to scanning gate microscopy (SGM). Here, we discuss spatially resolved SGM images of low-temperature charge transport through a mesoscopic ring fabricated from high-quality monolayer graphene lying on top of hexagonal boron nitride. SGM images are decorated with a pattern of radial scars in the ring area, which is found to evolve smoothly and reappear when varying the charge-carrier energy. The energies separating recurrent patterns are found to be directly related to geometric dimensions of the ring. Moreover, a recurrence is also observed in simulations of the local density of states of a model graphene quantum ring. The observed recurrences are discussed in the light of recent predictions of relativistic quantum scars in mesoscopic graphene cavities.
Nanoscopic Physics (NAPS), Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain (UCL) , Chemin du Cyclotron 2 bte L7.01.07, B-1348 Louvain-la-Neuve, Belgium.
Damien
0000-0003-0375-9402
D
Cabosart
Research Centre in Physics of Matter and Radiation (PMR), University of Namur (UNamur) , 61 rue de Bruxelles, B-5000 Namur, Belgium.
Alexandre
A
Felten
Research Centre in Physics of Matter and Radiation (PMR), University of Namur (UNamur) , 61 rue de Bruxelles, B-5000 Namur, Belgium.
Nicolas
N
Reckinger
Nanoscopic Physics (NAPS), Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain (UCL) , Chemin du Cyclotron 2 bte L7.01.07, B-1348 Louvain-la-Neuve, Belgium.
Andra
A
Iordanescu
Nanoscopic Physics (NAPS), Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain (UCL) , Chemin du Cyclotron 2 bte L7.01.07, B-1348 Louvain-la-Neuve, Belgium.
Sébastien
S
Toussaint
Institute of Information and Communication Technologies, Electronics and Applied Mathematics/WINFAB, Université catholique de Louvain (UCL) , Place du Levant 3 bte L5.03.04, B-1348 Louvain-la-Neuve, Belgium.
Sébastien
S
Faniel
Nanoscopic Physics (NAPS), Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain (UCL) , Chemin du Cyclotron 2 bte L7.01.07, B-1348 Louvain-la-Neuve, Belgium.
Benoît
B
Hackens
Graphene; coherent transport; mesoscopic transport; quantum scars; relativistic Dirac particles; scanning gate microscopy