Springer LINK: The European Physical Journal B - Abstract Volume 5 Issue 4 (1998) pp 913-917

The European Physical Journal B

ISSN: 1434-6028 (printed version)
ISSN: 1434-6036 (electronic version)

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Abstract Volume 5 Issue 4 (1998) pp 913-917

Phase behavior of coherent tunneling through a quantum dot: A consideration of the off-diagonal elastic coupling

Q. Sun (1), T. Lin (1)(2) (a)

(1) Department of Physics, Peking University, Beijing 100871, P.R. China
(2) CCAST, World Laboratory, P.O. BOX 8730, Beijing 100080, P.R. China

Received: 12 February 1998 / Revised: 28 May 1998 / Accepted: 29 May 1998

Abstract: The electron transmission amplitude through a quantum dot is studied by considering all elastic coupling elements, not only the diagonal elements $\Gamma_{jj}$,but also the off-diagonal elements $\Gamma_{ij}$.The Breit-Winger formula is extended to multiple states under the above consideration. The phase of the transmission amplitude exhibits a gradual increase by $\pi$ along a resonance peak and an abrupt phase drop by $\pi$ near the center between two consecutive resonance peaks which can be explained completely in a single-electron picture. When the temperature ${\cal T}=0$ the phase drop is absolutely abrupt; when ${\cal T}\not=0$ the phase drop is on a energy scale much smaller than both $\Gamma_{jj}$ and $k_B{\cal T}$.In addition, at the phase-drop-point, some interesting manifestations are predicted.

PACS. 73.40.Gk Tunneling[:AND:] 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)

(a) email: thlin@sun.ihep.ac.cn

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