TY - JOUR
T1 - Interaction-Driven Giant Orbital Magnetic Moments in Carbon Nanotubes
AU - Island, Joshua O.
AU - Ostermann, Marvin
AU - Aspitarte, Lee
AU - Minot, Ethan D.
AU - Varsano, Daniele
AU - Molinari, Elisa
AU - Rontani, Massimo
AU - Steele, Gary A.
PY - 2018
Y1 - 2018
N2 - Carbon nanotubes continue to be model systems for studies of confinement and interactions. This is particularly true in the case of so-called "ultraclean" carbon nanotube devices offering the study of quantum dots with extremely low disorder. The quality of such systems, however, has increasingly revealed glaring discrepancies between experiment and theory. Here, we address the outstanding anomaly of exceptionally large orbital magnetic moments in carbon nanotube quantum dots. We perform low temperature magnetotransport measurements of the orbital magnetic moment and find it is up to 7 times larger than expected from the conventional semiclassical model. Moreover, the magnitude of the magnetic moment monotonically drops with the addition of each electron to the quantum dot directly contradicting the widely accepted shell filling picture of single-particle levels. We carry out quasiparticle calculations, both from first principles and within the effective-mass approximation, and find the giant magnetic moments can only be captured by considering a self-energy correction to the electronic band structure due to electron-electron interactions.
AB - Carbon nanotubes continue to be model systems for studies of confinement and interactions. This is particularly true in the case of so-called "ultraclean" carbon nanotube devices offering the study of quantum dots with extremely low disorder. The quality of such systems, however, has increasingly revealed glaring discrepancies between experiment and theory. Here, we address the outstanding anomaly of exceptionally large orbital magnetic moments in carbon nanotube quantum dots. We perform low temperature magnetotransport measurements of the orbital magnetic moment and find it is up to 7 times larger than expected from the conventional semiclassical model. Moreover, the magnitude of the magnetic moment monotonically drops with the addition of each electron to the quantum dot directly contradicting the widely accepted shell filling picture of single-particle levels. We carry out quasiparticle calculations, both from first principles and within the effective-mass approximation, and find the giant magnetic moments can only be captured by considering a self-energy correction to the electronic band structure due to electron-electron interactions.
UR - http://resolver.tudelft.nl/uuid:70926ccf-49c8-4c95-a6b2-ef6ec9cc0434
UR - http://www.scopus.com/inward/record.url?scp=85053824125&partnerID=8YFLogxK
U2 - 10.1103/PhysRevLett.121.127704
DO - 10.1103/PhysRevLett.121.127704
M3 - Article
AN - SCOPUS:85053824125
SN - 0031-9007
VL - 121
JO - Physical Review Letters
JF - Physical Review Letters
IS - 12
M1 - 127704
ER -