A scheme to realize an optical switch with quantum coherence between its ``open'' and ``closed'' states is presented. It involves a single atom in a superposition of circular Rydberg states crossing a high Q cavity. A combination of switches could be used to prepare a quantum superposition of coherent microwave field states located simultaneously in two cavities. Such nonclassical states and their decoherence due to cavity dissipation could be studied by performing atom correlation experiments.A scheme to realize an optical switch with quantum coherence between its ``open'' and ``closed'' states is presented. It involves a single atom in a superposition of circular Rydberg states crossing a high Q cavity. A combination of switches could be used to prepare a quantum superposition of coherent microwave field states located simultaneously in two cavities. Such nonclassical states and their decoherence due to cavity dissipation could be studied by performing atom correlation experiments.

Physical Review LettersOct 11, 1993178 citations

Spectroscopy of Rydberg atoms in a high-magnetic-field atom trap

Eric Paradis, Stefan Zigo, Georg A. Raithel

Bulletin of the American Physical SocietyJun 14, 20110 citations

A dual-pulse heterodyne detection scheme for tunable temporal weak-value amplification towards unshielded Faraday magnetometry

Md Tousif Alam, Surya Narayan Sahoo, Nandini Mondal +2 more

Abstract When a polarized optical pulse propagates through a Faraday medium, the two circular polarization eigenmodes accumulate differential phase shifts and differential group delay. These two eigenmodes thus become distinguishable by the arrival time of photons, which can serve as a pointer state in the weak-measurement (WM) framework. Here, we describe the Faraday effect as a von Neumann-type interaction, coupling the polarization degree of freedom of light to the temporal envelope of the pulse. Under suitable pre- and post-selection of nearly orthogonal linear polarizations, the two delayed circular components interfere spectrally. This produces an amplified spectral centroid shift, corresponding to the imaginary weak value of the circular polarization component, which is highly sensitive to the small phase shifts induced by the Faraday effect. We propose detecting this spectral shift using heterodyne detection by measuring the centroid of the radio-frequency beat spectrum, a method suitable for atomic magnetometry. While this single-pulse approach may be viable where steep dispersion near resonance yields considerable group delay, it would be ineffective in most far-off-resonant magnetometry where group delay is insignificant. We propose to overcome this challenge by employing two oppositely circularly polarized pulses with a controllable phase difference and a synthetic temporal delay. These engineered input pulses provide tunable sensitivity by allowing weak-value amplification for detecting small magnetic field variations, even in the presence of an ambient magnetic field. Crucially, because the post-selection process prevents detector saturation, it allows for the use of significantly higher optical power, up to the atomic saturation level. For far-off-resonant Faraday magnetometry, we estimate that this detection scheme could potentially allow 10–100 femtotesla-level ( fT Hz − 1 ) photon-shot-noise-limited sensitivity for thermal alkali-vapors depending on detuning, with microtesla-level tunable dynamic range. Hence, this WM-based heterodyne spectral centroid readout scheme can mitigate technical noise, paving the way for high-sensitivity alkali-vapor magnetometry in unshielded environments.Abstract When a polarized optical pulse propagates through a Faraday medium, the two circular polarization eigenmodes accumulate differential phase shifts and differential group delay. These two eigenmodes thus become distinguishable by the arrival time of photons, which can serve as a pointer state in the weak-measurement (WM) framework. Here, we describe the Faraday effect as a von Neumann-type interaction, coupling the polarization degree of freedom of light to the temporal envelope of the pulse. Under suitable pre- and post-selection of nearly orthogonal linear polarizations, the two delayed circular components interfere spectrally. This produces an amplified spectral centroid shift, corresponding to the imaginary weak value of the circular polarization component, which is highly sensitive to the small phase shifts induced by the Faraday effect. We propose detecting this spectral shift using heterodyne detection by measuring the centroid of the radio-frequency beat spectrum, a method suitable for atomic magnetometry. While this single-pulse approach may be viable where steep dispersion near resonance yields considerable group delay, it would be ineffective in most far-off-resonant magnetometry where group delay is insignificant. We propose to overcome this challenge by employing two oppositely circularly polarized pulses with a controllable phase difference and a synthetic temporal delay. These engineered input pulses provide tunable sensitivity by allowing weak-value amplification for detecting small magnetic field variations, even in the presence of an ambient magnetic field. Crucially, because the post-selection process prevents detector saturation, it allows for the use of significantly higher optical power, up to the atomic saturation level. For far-off-resonant Faraday magnetometry, we estimate that this detection scheme could potentially allow 10–100 femtotesla-level ( fT Hz − 1 ) photon-shot-noise-limited sensitivity for thermal alkali-vapors depending on detuning, with microtesla-level tunable dynamic range. Hence, this WM-based heterodyne spectral centroid readout scheme can mitigate technical noise, paving the way for high-sensitivity alkali-vapor magnetometry in unshielded environments.

Physica ScriptaOct 16, 20260 citations

Generation of Einstein-Podolsky-Rosen Pairs of Atoms

E. W. Hagley, Xavier Maı̂tre, Gilles Nogues +4 more

Pairs of atoms have been prepared in an entangled state of the Einstein-Podolsky-Rosen (EPR) type. They were produced by the exchange of a single photon between the atoms in a high $Q$ cavity. The atoms, entangled in a superposition involving two different circular Rydberg states, were separated by a distance of the order of 1 cm. At variance with most previous EPR experiments, this one involves massive particles. It can be generalized to three or more atoms and opens the way to new tests of nonlocality in mesoscopic quantum systems.Pairs of atoms have been prepared in an entangled state of the Einstein-Podolsky-Rosen (EPR) type. They were produced by the exchange of a single photon between the atoms in a high $Q$ cavity. The atoms, entangled in a superposition involving two different circular Rydberg states, were separated by a distance of the order of 1 cm. At variance with most previous EPR experiments, this one involves massive particles. It can be generalized to three or more atoms and opens the way to new tests of nonlocality in mesoscopic quantum systems.

Physical Review LettersJul 7, 1997808 citations

Magnetic trapping of circular Rydberg atoms

David Alexander Anderson, Andrew Schwarzkopf, Georg A. Raithel

Bulletin of the American Physical SocietyJun 5, 20130 citations

Pairs of atoms have been prepared in an entangled state of the Einstein-Podolsky-Rosen (EPR) type. They were produced by the exchange of a single photon between the atoms in a high

Q

cavity. The atoms, entangled in a superposition involving two different circular Rydberg states, were separated by a distance of the order of 1 cm. At variance with most previous EPR experiments, this one involves massive particles. It can be generalized to three or more atoms and opens the way to new tests of nonlocality in mesoscopic quantum systems.