Single Atom and Two Atom Ramsey Interferometry with Quantized Fields

Implications of field quantization on Ramsey interferometry are discussed and general conditions for the occurrence of interference are obtained. Interferences do not occur if the fields in two Ramsey zones have precise number of photons. However in this case we show how two atom (like two photon) interferometry can be used to discern a variety of interference effects as the two independent Ramsey zones get entangled by the passage of first atom. Generation of various entangled states like |0,2>+|2,0> are discussed and in far off resonance case generation of entangled state of two coherent states is discussed.Comment: 20 pages, 5 figures, revised version. submitted to Phys. Rev.

COHERENT EXCITATION OF A 2-STATE SYSTEM BY A TRAIN OF SHORT PULSES

Published versio

Lamb shift measurement in the 1 S-1 ground state of helium

With a phase-modulated extreme ultraviolet pulsed laser sourer the frequency of the I S-1-2 P-1 transition of helium at 58 nm has been measured. Thr phase modulation scheme enabled measurement and reduction of frequency chirp. usually limiting pulsed precision spectroscopy. From the measured transition frequency of 5 130 395 083(45) MHz, a fourfold improved value of the ground state Lamb shift of 41 224(45) MHz is deduced, in good agreement with a theoretical value of 41 233(35) MHz based on QED calculations up to order alpha(5)Z(6). From these measurements, the well-known binding energy of the 2 P-1 state and the previously determined He-4-He-3 isotope shift. accurate values for the ionization energies of the helium atom follow: 198 310.6672(15) cm(-1) for He-4 and 198.301.8808(15) cm(-1) for He-3