Jürgen Appel - Academia.edu (original) (raw)
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Papers by Jürgen Appel
Latin America Optics and Photonics Conference, 2010
ABSTRACT Using shot noise limited Quantum-Non-Demolition measurements, we prepare an entangled, s... more ABSTRACT Using shot noise limited Quantum-Non-Demolition measurements, we prepare an entangled, spin squeezed ensemble of 105 cold Cs atoms, which we use to improve the precision of an atomic clock by >1 dB beyond the projection noise limit. We report on progress towards applying our method for realizing and characterizing non-Gaussian atomic states.
Journal of Modern Optics, 2009
We provide a framework for understanding recent experiments on squeezing of a collective atomic p... more We provide a framework for understanding recent experiments on squeezing of a collective atomic pseudo-spin, induced by a homodyne measurement on off-resonant probe light interrogating the atoms. The detection of light decimates the atomic state distribution and we discuss the conditions under which the resulting reduced quantum fluctuations are metrologically relevant. In particular, we consider a dual probe scheme which benefits from a cancelation of classical common mode noise sources such that quantum fluctuations from light and atoms are the main contributions to the detected signal.
New Journal of Physics, 2010
We use a quantum non-demolition measurement to generate a spin squeezed state and to create entan... more We use a quantum non-demolition measurement to generate a spin squeezed state and to create entanglement in a cloud of 10 5 cold cesium atoms, and for the first time operate an atomic clock improved by spin squeezing beyond the projection noise limit in a proof-of-principle experiment. For a clock-interrogation time of 10 µs the experiments show an improvement of 1.1 dB in the signal-to-noise ratio, compared to the atomic projection noise limit.
Latin America Optics and Photonics Conference, 2010
ABSTRACT Using shot noise limited Quantum-Non-Demolition measurements, we prepare an entangled, s... more ABSTRACT Using shot noise limited Quantum-Non-Demolition measurements, we prepare an entangled, spin squeezed ensemble of 105 cold Cs atoms, which we use to improve the precision of an atomic clock by >1 dB beyond the projection noise limit. We report on progress towards applying our method for realizing and characterizing non-Gaussian atomic states.
Journal of Modern Optics, 2009
We provide a framework for understanding recent experiments on squeezing of a collective atomic p... more We provide a framework for understanding recent experiments on squeezing of a collective atomic pseudo-spin, induced by a homodyne measurement on off-resonant probe light interrogating the atoms. The detection of light decimates the atomic state distribution and we discuss the conditions under which the resulting reduced quantum fluctuations are metrologically relevant. In particular, we consider a dual probe scheme which benefits from a cancelation of classical common mode noise sources such that quantum fluctuations from light and atoms are the main contributions to the detected signal.
New Journal of Physics, 2010
We use a quantum non-demolition measurement to generate a spin squeezed state and to create entan... more We use a quantum non-demolition measurement to generate a spin squeezed state and to create entanglement in a cloud of 10 5 cold cesium atoms, and for the first time operate an atomic clock improved by spin squeezing beyond the projection noise limit in a proof-of-principle experiment. For a clock-interrogation time of 10 µs the experiments show an improvement of 1.1 dB in the signal-to-noise ratio, compared to the atomic projection noise limit.