https://doi.org/10.1007/s100510050517
Phase behavior of coherent tunneling through a quantum dot: A consideration of the off-diagonal elastic coupling
1
Department of Physics, Peking University,
Beijing 100871, P.R. China
2
CCAST, World Laboratory, P.O. BOX 8730, Beijing 100080, P.R. China
Corresponding author: a thlin@sun.ihep.ac.cn
Received:
12
February
1998
Revised:
28
May
1998
Accepted:
29
May
1998
Published online: 15 October 1998
The electron transmission amplitude through a quantum dot is studied
by considering all elastic coupling elements,
not only the diagonal elements 
,
but also the off-diagonal elements 
.
The Breit-Winger formula is extended to multiple states under the
above consideration. The phase of
the transmission amplitude exhibits
a gradual increase by π along a resonance peak and
an abrupt phase drop by π near
the center between two consecutive resonance peaks
which can be explained completely in a single-electron picture.
When the temperature 
the phase drop is absolutely abrupt;
when 
the phase drop is
on a energy scale much smaller than both and 
.
In addition, at the phase-drop-point, some interesting
manifestations are predicted.
PACS: 73.40.Gk – Tunneling / 85.30.Vw – Low-dimensional quantum devices (quantum dots, quantum wires etc.) / 73.20.Dx – Electron states in low-dimensional structures (superlattices, quantum well structures and multilayers)
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1998
