[en] We establish a new integral transform that reveals the relation of the density operator to the Husimi operator. The connection between the Husimi function of a given state (i.e. position-momentum-intermediate representation) and the tomography of an arbitrary quantum state is revealed. (paper)

[en] The authors present and α and β radiation system of counting emission from up four samples simultaneously. The primary detectors are made of the new low background α and β scintillator of model ST 1221 and the low noise PM tube model GDB-52LD. A single 300 mm x 50 mm plastic scintillator is used as guard detector. ⁹⁰Sr-⁹⁰Y counting efficiency is 60% with typical background of 0.03/cm² · min, counting efficiency for ²³⁹Pu is 70% with background of 0.03/cm²· h. This instrument is compatible with microcomputer of any type. Measuring and data processing are controlled by computer

[en] In this paper, we propose two physical schemes for teleporting an unknown atomic state through noisy channel in cavity QED. The quantum channel is a noisy one - a mixed GHZ state, which is more realistic in quantum information processing. We solve analytically a master equation in the Lindblad form with (L_2,z, L_3,z, L_4,z)-type of noise in cavity QED. A comparison between the two protocols are discussed. (general)

[en] An efficient pulsed CH₃OH terahertz (THz) laser pumped by a TEA CO₂ laser is investigated experimentally. To improve photon conversion efficiency and THz laser energy, two cavity configurations of the TEA CO₂ laser, which is external and semi-external, are evaluated. The pump intensities are about 4.7 MW/cm² and 1.2 MW/cm², respectively. Higher pump intensity and more stable single lines are obtained in the external cavity. For the 3.8 J pump energy of the 9P(16) transition in the external cavity, the maximum terahertz output energy with 570.5 μm wavelength at 160 Pa is 431 μJ. With a 6 J energy pulse in terms of a semi-external cavity, a 353 μJ terahertz emission (570.5 μm) is produced. The corresponding photon conversion efficiencies are 1.36% and 0.705%, increasing by a factor of about 2. (fundamental areas of phenomenology(including applications))

[en] We present a deterministic scheme for generating large scale GHZ states in a cavity-quantum dot system. A singly charged quantum dot is embedded in a double-sided optical microcavity with partially reflective top and bottom mirrors. The GHZ-type Bell spin state can be created and two n-spin GHZ states can be perfectly fused to a 2n-spin GHZ state with the help of n ancilla single-photon pulses. The implementation of the current scheme only depends on the photon detection and its need not to operate multi-qubit gates and multi-qubit measurements. Discussions about the effect of the cavity loss, side leakage and exciton cavity coupling strength for the fidelity of generated states show that the fidelity can remain high enough by controlling system parameters. So the current scheme is simple and feasible in experiment. (letter)