TY  - JOUR
A1  - Sessi, Paolo
A1  - Silkin, Vyacheslav M.
A1  - Nechaev, Ilya A.
A1  - Bathon, Thomas
A1  - El-Kareh, Lydia
A1  - Chulkov, Evgueni V.
A1  - Echenique, Pedro M.
A1  - Bode, Matthias
T1  - Direct observation of many-body charge density oscillations in a two-dimensional electron gas
T2  - Nature Communications
N2  - Quantum interference is a striking manifestation of one of the basic concepts of quantum mechanics: the particle-wave duality. A spectacular visualization of this effect is the standing wave pattern produced by elastic scattering of surface electrons around defects, which corresponds to a modulation of the electronic local density of states and can be imaged using a scanning tunnelling microscope. To date, quantum-interference measurements were mainly interpreted in terms of interfering electrons or holes of the underlying band-structure description. Here, by imaging energy-dependent standing-wave patterns at noble metal surfaces, we reveal, in addition to the conventional surface-state band, the existence of an 'anomalous' energy band with a well-defined dispersion. Its origin is explained by the presence of a satellite in the structure of the many-body spectral function, which is related to the acoustic surface plasmon. Visualizing the corresponding charge oscillations provides thus direct access to many-body interactions at the atomic scale.
KW  - scanning tunneling spectroscopy
KW  - acoustic surface plasmon
KW  - metal surfaces
KW  - Cu(111)
KW  - excitations
KW  - microscopy
KW  - local density
KW  - standing wave formation
KW  - states
KW  - steps
Y1  - 2015
UR  - https://opus.bibliothek.uni-wuerzburg.de/frontdoor/index/index/docId/14524
UR  - https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-145246
VL  - 6
IS  - 8691
ER  -