Thrusday seminar - for distribution

[CM ICTP - Trieste]

SEMINAR on   Disorder and strong electron correlations



Thursday, 20 September   -    11:00 a.m.


Seminar Room,  Main Bldg.- first floor



K. KIKOIN   ( Tel-Aviv University )

"Decoherence and dephasing in quantum dots with SO(5) dynamical 
symmetry"

Abstract

	Complex quantum dots are characterized by non-trivial dynamical 
symmetries SU(n)(in case of odd electron occupation) or SO(n) (in case 
of even occupation).  These symmetries are activated due to interaction 
with environment, i.e. metallic electrons in source and drain leads, 
and due to influence of external electrical and magnetic field.
	Incoherent charge input signal applied to double quantum dot may be 
transformed into incoherent response in Kondo-type tunnel conductance, 
and the transformation mechanism is intimately connected with gauge 
fluctuations because of time-dependent violation of SO(5) symmetry.  
The difference between dephasing and decoherence processes induced by 
external noise will be demonstrated explicitly.