Multiphoton coherent driving in harmonic and non-harmonic spin systems

1
Multiphoton coherent driving in harmonic and
non-harmonic spin systems
Irinel Chiorescu- Dept of Physics FSU NHMFL
2
(No Transcript)
3
www.physics.fsu.edu
Tallahassee, FL
Graduate Program! www.physics.fsu.edu
4
Collaborators

• postdoc Sylvain Bertaina (moving to
  CNRS-Marseille, France)
• grad students Nick Groll, Lei Chen

Dept. of Chemistry, Florida State Univ.
Prof. Naresh Dalal The EPR group at
NHMFL Dr. J. van Tol Dr. S.
Nellutla
Dept of Physics, Michigan State University
Prof. M. Dykman
Funding NSF-Career, DARPA, NHMFL, Alfred P.
Sloan Foundation
5
Spin coherence with Mn spins

• Mn diluted in MgO single crystal
• Spin Hamiltonian

H a/6 Sx4Sy4Sz4- S(S1)(3S2-1)/5
gmBH0S-ASI
g 2.0025, a 55.7 MHz, A 244 MHz, S I 5/2
6
Room Temperature Spectroscopy Data
Spin levels, fixed mI anisotropy ? non-harmonic
5/2
3/2
1/2
-1/2
-3/2
-5/2
At low power, for a given mI, one see mostly the
central resonance -1/2 ? 1/2
DmI0, DmS1
7
Continuous wave multiphoton spectroscopy
H0 110, mI-3/2
8
Room temperature Rabi oscillations

• EPR measurement of ltSxgt by Free Induction Decay
  method
• Rabi frequency 21 MHz
• Rabi decay time 200 ns

mI-5/2, H0 100
9
Multi-photon/multi-level spin control
4
2
Calculated dressed states diagrams. The level
splittings give the Rabi frequency corresponding
to each multi-photon coherent qubit nutation.
Rabi oscillations showing ltSzgt as a function of
MW pulse length for different MW powers.
H0 (1,0.8,1), mI-3/2
10
Numerical Simulations
S. Bertaina (FSU CNRS-Marseille, France)

• Anisotropy and hyperfine terms ltlt Zeeman term
• neglect forbidden transition, that is DmI0
  indeed.
• diagonalize H in a given mI subspace ? HmI
• external field good quantization axis , apply
  RFA HmI ? static Hrot
• diagonalize Hrot ? energy diagram (dressed
  states picture)
• time evolution of the density matrix ? time and
  temperature dependence of ltSx,y,zgt

(Gaussian profile for the resonance)
11
Effect of anisotropy
12
The compensation angle
13
Non-harmonic ? Harmonic
Rabi frequency in a two level system
hFRcomp 1/2 gmBhmw
Rabi frequency between two consecutive levels,
in a multi-level system
hFR1 1/2 gmBhmw ?(S(S1)-Sz(Sz1))
Sz -1/2 ? 1/2 , for q around 0
FR1/FRcomp 53.5 MHz / 18.07 MHz 2.96
At qqcomp non-harmonic ? harmonic multi-level
system with a 2-level system dynamics
14
Multi-photon Rabi oscillations
T40K, H0 101 and mI-3/2
15
Qcomp at room temperature
RT, hmw0.52 mT FR1/FRcomp 21 MHz / 7 MHz
3 (to be compared with 2.96 at hmw1.34 mT)