25,225 research outputs found
Adiabatic State Conversion and Pulse Transmission in Optomechanical Systems
Optomechanical systems with strong coupling can be a powerful medium for
quantum state engineering. Here, we show that quantum state conversion between
cavity modes with different wavelengths can be realized with high fidelity by
adiabatically varying the effective optomechanical couplings. The fidelity for
the conversion of gaussian states is derived by solving the Langevin equation
in the adiabatic limit. We also show that photon pulses can be transmitted
between input-output channels with different wavelengths via the effective
optomechanical couplings and the output pulse shape can also be manipulated.Comment: 5 pages, 2 figures. Supplementary Materials at
http://prl.aps.org/supplemental/PRL/v108/i15/e15360
Charge-stripe order in the electronic ferroelectric LuFe2O4
The structural features of the charge ordering states in LuFe2O4 are
characterized by in-situ cooling TEM observations from 300K down to 20K. Two
distinctive structural modulations, a major q1= (1/3, 1/3, 2) and a weak
q2=q1/10 + (0, 0, 3/2), have been well determined at the temperature of 20K.
Systematic analysis demonstrates that the charges at low temperatures are well
crystallized in a charge stripe phase, in which the charge density wave
behaviors in a non-sinusoidal fashion resulting in elemental electric dipoles
for ferroelectricity. It is also noted that the charge ordering and
ferroelectric domains often change markedly with lowering temperatures and
yields a rich variety of structural phenomena.Comment: 15 pages, 4 figure
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