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| VOLUME 102 (2015) | ISSUE 2 | PAGE 120 |
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Unusual narrowing of the ESR line width in ordered structures with linear chains of Ge/Si quantum dots
A. F. Zinovieva+, Zh. V. Smagina+, A. V. Nenashev+*, L. V. Kulik*×, A. V. Dvurechenskii+*
+Rzhanov Institute of Semiconductor Physics SB of the RAS, 630090 Novosibirsk, Russia *Novosibirsk State University, 630090 Novosibirsk, Russia ×Voevodsky Institute of Chemical Kinetics and Combustion SB of the RAS, 630090 Novosibirsk, Russia
Abstract
Electron states in ordered Ge/Si heterostructures with linear chains of quantum dots (QDs) were studied by the electron spin resonance (ESR) method. A new ESR signal with principal g-factor values  ,
 was detected.
Unlike non-ordered QD structures,
where ESR line broadening is usually observed (evidence of
Dyakonov-Perel mechanism efficiency), the structures under study
demonstrate the narrowing of ESR line when the external magnetic
field deviates from the growth direction. The ESR line width is
Δ H=1.2 Oe for perpendicular magnetic field (along the growth
direction) and Δ H=0.8 Oe for in-plane magnetic field. The
narrowing of ESR line can be explained by combination of two
mechanisms. The first one is suppression of Dyakonov-Perel spin
relaxation due to a settled direction of electron motion and
finiteness of QD chains. The second one is cancelation of the wave
function shrinking effect with decreasing the perpendicular
component of the magnetic field.
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