EELS quantification near the single-atom detection level

Upconversion detection near 2 μm at the single photon level.

We have demonstrated upconversion detection at the single photon level in the 2 μm spectral window using a pump wavelength near 1550 nm, a periodically poled lithium niobate (PPLN) waveguide, and a volume Bragg grating (VBG) to reduce noise. We achieve a system photon detection efficiency of 10%, with a noise count rate of 24,500 counts per second, competitive with other 2 μm single photon dete...

Atom-atom entanglement by single-photon detection.

A scheme for entangling distant atoms is realized, as proposed in the seminal paper by [C. Cabrillo et al., Phys. Rev. A 59, 1025 (1999)]. The protocol is based on quantum interference and detection of a single photon scattered from two effectively one meter distant laser cooled and trapped atomic ions. The detection of a single photon heralds entanglement of two internal states of the trapped ...

Photon entanglement detection by a single atom

We use a single trapped 40Ca ion as a resonant, polarizationsensitive absorber to detect and characterize the entanglement of tunable narrowband photon pairs from a spontaneous parametric down-conversion source. Single-photon absorption is marked by a quantum jump in the ion and heralded by coincident detection of the partner photon. For three polarization basis settings of the absorption and d...

Model based quantification of EELS spectra.

Recent advances in model based quantification of electron energy loss spectra (EELS) are reported. The maximum likelihood method for the estimation of physical parameters describing an EELS spectrum, the validation of the model used in this estimation procedure, and the computation of the attainable precision, that is, the theoretical lower bound on the variance of these estimates, are discusse...

Near-Infrared Single-Photon Detection