Microwave spectroscopy on a quantum-dot molecule

Quantum dots are small conductive regions in a semiconductor, containing a variable number of electrons (N=1 to 1000) that occupy well defined discrete quantum states. They are often referred to as artificial atoms with the unique property that they can be connected to current and voltage contacts....

Full description

Saved in:
Bibliographic Details
Published inarXiv.org
Main Authors Oosterkamp, T H, Fujisawa, T, W G van der Wiel, Ishibashi, K, Hijman, R V, Tarucha, S, Kouwenhoven, L P
Format Paper
LanguageEnglish
Published Ithaca Cornell University Library, arXiv.org 09.09.1998
Subjects
Binding
Bonding strength
Coherence
Coupling
Coupling (molecular)
Covalence
Energy spectra
Quantum dots
Quantum phenomena
Single electrons
Spectrum analysis
Online AccessGet full text

Cover

More Information
Summary:Quantum dots are small conductive regions in a semiconductor, containing a variable number of electrons (N=1 to 1000) that occupy well defined discrete quantum states. They are often referred to as artificial atoms with the unique property that they can be connected to current and voltage contacts. This allows one to use transport measurements to probe the discrete energy spectra. To continue the analogy with atoms, two quantum dots can be connected to form an 'artificial molecule'. Depending on the strength of the inter-dot coupling, the two dots can have an ionic binding (i.e. electrons are localized on the individual dots) or a covalent binding (i.e. electrons are delocalized over both dots). The covalent binding leads to a bonding and an anti-bonding state with an energy splitting proportional to the tunnel coupling. In the dc current response to microwave excitation we observe a transition from an ionic bonding to a covalent bonding, when we vary the inter-dot coupling strength. This demonstrates controllable quantum coherence in single electron devices.
ISSN:2331-8422