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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 2:23 |
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Conference: Bucharest University Faculty of Physics 2003 Meeting
Section: Solid State Physics and Materials Science
Title:
Single-chip device for measuring tunneling times through mesoscopic structures
Authors:
Daniela Dragoman (1), Mircea Dragoman (2)
Affiliation:
(1) Univ. of Bucharest, Physics Dept., P.O. Box MG-11, 76900 Bucharest, Romania
(2) National Inst. of Microtechnology, P.O. Box 38-160, 72225 Bucharest, Romania
E-mail
Keywords:
Abstract:
A single-chip mesoscopic device is proposed for measurements of the tunneling time of electrons or holes through various mesoscopic structures. The method is based on the possibility of employing a surface acoustic wave for the generation of spatially separated electrons and holes that are transported with a controlled velocity and separation over a quantum wire. The quantum wire splits then into two quantum wires/waveguides through which electrons and, respectively, holes are transported, the charge carriers being separated in the respective waveguides by applying electric fields with opposite signs in the splitting region. A succession of barriers with a controllable height can be implemented along the electron or the hole waveguide through a number of point contacts situated at a desired separation. After propagating through carefully controlled distances the electrons and holes are allowed to recombine, their coincidence (measured with a one-photon detector, for example) taking place if the tunneling time of one type of carriers through an engineered mesoscopic structure is compensated by the magnetic field induced delay of the other carrier type. Extremely fast tunneling times of either electrons or holes through various mesoscopic structures can be measured in this way by recording the magnetic field needed to realize the coincidence of electrons and holes at the detector.
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