7 research outputs found
Linear optical properties of one-dimensional Frenkel exciton systems with intersite energy correlations
We analyze the effects of intersite energy correlations on the linear optical
properties of one-dimensional disordered Frenkel exciton systems. The
absorption line width and the factor of radiative rate enhancement are studied
as a function of the correlation length of the disorder. The absorption line
width monotonously approaches the seeding degree of disorder on increasing the
correlation length. On the contrary, the factor of radiative rate enhancement
shows a non-monotonous trend, indicating a complicated scenario of the exciton
localization in correlated systems. The concept of coherently bound molecules
is exploited to explain the numerical results, showing good agreement with
theory. Some recent experiments are discussed in the light of the present
theory.Comment: 18 pages, 3 figues, REVTeX, to appear in Physical Review
Electroluminescent nanocomposites based on molecular crystals for polymer optoelectronics. Part 2
Tunka-Rex: Status and results of the first measurements
Tunka-Rex is the radio extension of Tunka-133 located in Siberia close to
Lake Baikal. The latter is a photomultiplier array registering air-Cherenkov
light from air showers induced by cosmic-ray particles with initial energies of
approximately to eV. Tunka-Rex extends this detector with
25 antennas spread over an area of 1 km. It is triggered externally by
Tunka-133, and detects the radio emission of the same air showers. The
combination of an air-Cherenkov and a radio detector provides a facility for
hybrid measurements and cross-calibration between the two techniques. The main
goal of Tunka-Rex is to determine the precision of the reconstruction of
air-shower parameters using the radio detection technique. It started operation
in autumn 2012. We present the overall concept of Tunka-Rex, the current status
of the array and first analysis results.Comment: RICAP 2013 proceedings, 6 pages, 13 figure