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CATEGORIES:AMOP list
SUMMARY:Optical control and dynamics of a single Mn spin i
 n a CdTe/ZnTe quantum dot - Claire Le Gall (Grenob
 le)
DTSTART;TZID=Europe/London:20110516T153000
DTEND;TZID=Europe/London:20110516T170000
UID:TALK31303AThttp://talks.cam.ac.uk
URL:http://talks.cam.ac.uk/talk/index/31303
DESCRIPTION:A Manganese Atom is added in the CdTe crystal of a
  II-VI quantum dot\, forming a 5/2 localised spin.
  The spd-exchange interactions between this Mn ato
 m and a photo-created electron-hole pair results i
 n the emission of a photon at a given energy depen
 ding on the spin-state of the Mn atom [1]. In othe
 r words\, it is possible to access optically the M
 n spin-state. We will show in this talk that it is
  possible to control the orientation of the Mn spi
 n optically using quasi-resonant excitation [2] or
  resonant excitation [3]. The pumping process is d
 irectly observed through time-resolved experiments
 . Relaxation of the Mn spin can be accessed optica
 lly and T1 is found to be much longer than 10 micr
 o-seconds. We will discuss the physics ruling this
  process: the observed Mn optical orientation can 
 be explained by carrier spin-relaxation towards da
 rk states as proposed by L. Cyvinsky in [4]\, in c
 onjunction with a strained-induced crystal field a
 long the growth axis that guarantees the conservat
 ion of the Mn spin-state Sz between the injection 
 of two excitons even at B=0T. At last\, we will re
 port on the observation of optically dressed state
 s and optical stark effect performed on any given 
 spin-state of the Mn atom [5]\, which is a first s
 tep toward a coherent control of the Mn spin.\n\n[
 1] L. Besombes\, Y. Leger\, L. Maingault\, D. Ferr
 and\, H. Mariette "Probing the spin state of a sin
 gle Magnetic ion in an individual quantum dot" Phy
 s Rev Lett 93\, 207403 (2004)\n\n[2] C. Le Gall\, 
 L. Besombes\, H. Boukari\, R. Kolodka\, J. Cibert\
 , and H. Mariette "Optical Spin Orientation of a S
 ingle Manganese Atom in a Semiconductor Quantum Do
 t Using Quasiresonant Photoexcitation"\, Phys Rev 
 Lett 102\, 127402 (2009)\n\n[3] C. Le Gall\, R. S.
  Kolodka\, C. L. Cao\, H. Boukari\, H. Mariette\, 
 J. Fernández-Rossier\, and L. Besombes "Optical in
 itialization\, readout\, and dynamics of a Mn spin
  in a quantum dot" Phys Rev B 81\, 245315 (2010)\n
 \n[4] L. Cyvinski\, "Optical orientation of a sing
 le Mn spin in a quantum dot: Role of carrier spin 
 relaxation"\, Phys Rev B 82\, 075321 (2010) \n\n[5
 ] C. Le Gall\, A. Brunetti\, H. Boukari\, L. Besom
 bes\, "Optical Stark Effect and Dressed Excitonic 
 States in a Mn-doped Quantum Dot" http://arxiv.org
 /abs/1104.3026\n\n \n\n
LOCATION:Rutherford building\, Seminar Room B
CONTACT:
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