Optical spectroscopy and development of quantum electronics

Andreas Günther, H. Bender, Alexander Stibor +2 more

We experimentally demonstrate optical spectroscopy of magnetically trapped atoms on an atom chip. High resolution optical spectra of individual trapped clouds are recorded within a few hundred milliseconds. Detection sensitivities close to the single atom level are obtained by photoionization of the excited atoms and subsequent ion detection with a channel electron multiplier. Temperature and decay rates of the trapped atomic cloud can be monitored in real time for several seconds with only little detection losses. The spectrometer can be used for investigations of ultracold atomic mixtures and for the development of interferometric quantum sensors on atom chips.

P. Arora, V. K. Chaubey

A.S. Shumovsky

Zhedong Zhang, Tao Peng, Xiaoyu Nie +2 more

Quantum entanglement has emerged as a great resource for spectroscopy and its importance in two-photon spectrum and microscopy has been demonstrated. Current studies focus on the two-photon absorption, whereas the Raman spectroscopy with quantum entanglement still remains elusive, with outstanding issues of temporal and spectral resolutions. Here we study the new capabilities provided by entangled photons in coherent Raman spectroscopy. An ultrafast frequency-resolved Raman spectroscopy with entangled photons is developed for condensed-phase molecules, to probe the electronic and vibrational coherences. Using quantum correlation between the photons, the signal shows the capability of both temporal and spectral resolutions not accessible by either classical pulses or the fields without entanglement. We develop a microscopic theory for this Raman spectroscopy, revealing the electronic coherence dynamics even at timescale of 50fs. This suggests new paradigms of optical signals and spectroscopy, with potential to push detection below standard quantum limit.

Wolfgang Wagner, Chunqiang Li, John L. Semmlow +1 more

Two dimensional magnetic and optical spectra contain information about structure and dynamics inaccessible to the linear spectroscopist. Recently, phase cycling techniques in optical spectroscopy have extended the capabilities of two-dimensional electronic spectroscopy. Here, we present a method to generate collinear pump/probe pulses at high update rates for two-dimensional electronic spectroscopy. Both fluorescence mode and transmission mode photon echo data from rubidium vapor is presented.