References of "Martin, John"
     in
Bookmark and Share    
See detailSpontaneous emission from a tunneling atom
Braun, Daniel; Martin, John ULg

Conference (2008, March)

Detailed reference viewed: 5 (0 ULg)
Full Text
Peer Reviewed
See detailMultifractality and intermediate statistics in quantum maps
Martin, John ULg; Giraud, O.; Georgeot, B.

in Physical Review. E : Statistical, Nonlinear, and Soft Matter Physics (2008), 77

We study multifractal properties of wave functions for a one-parameter family of quantum maps displaying the whole range of spectral statistics intermediate between integrable and chaotic statistics. We ... [more ▼]

We study multifractal properties of wave functions for a one-parameter family of quantum maps displaying the whole range of spectral statistics intermediate between integrable and chaotic statistics. We perform extensive numerical computations and provide analytical arguments showing that the generalized fractal dimensions are directly related to the parameter of the underlying classical map, and thus to other properties such as spectral statistics. Our results could be relevant for Anderson and quantum Hall transitions, where wave functions also show multifractality. [less ▲]

Detailed reference viewed: 18 (5 ULg)
Full Text
Peer Reviewed
See detailSpontaneous emission from a two-level atom tunneling in a double-well potential
Braun, Daniel; Martin, John ULg

in Physical Review. A (2008), 77

We study a two-level atom in a double-well potential coupled to a continuum of electromagnetic modes (black-body radiation in three dimensions at zero absolute temperature). Internal and external degrees ... [more ▼]

We study a two-level atom in a double-well potential coupled to a continuum of electromagnetic modes (black-body radiation in three dimensions at zero absolute temperature). Internal and external degrees of freedom of the atom couple due to recoil during emission of a photon. We provide a full analysis of the problem in the long wavelengths limit up to the border of the Lamb-Dicke regime, including a study of the internal dynamics of the atom (spontaneous emission), the tunneling motion, and the electric field of the emitted photon. The tunneling process itself may or may not decohere depending on the wavelength corresponding to the internal transition compared to the distance between the two wells of the external potential, as well as on the spontaneous emission rate compared to the tunneling frequency. Interference fringes appear in the emitted light from a tunneling atom, or an atom in a stationary coherent superposition of its center-of-mass motion, if the wavelength is comparable to the well separation, but only if the external state of the atom is post selected. [less ▲]

Detailed reference viewed: 26 (9 ULg)
Full Text
Peer Reviewed
See detailCooling by Time Reversal of Atomic Matter Waves
Martin, John ULg; Georgeot, B.; Shepelyansky, D. L.

in Physical Review Letters (2008), 100

We propose an experimental scheme which allows us to realized approximate time reversal of matter waves for ultracold atoms in the regime of quantum chaos. We show that a significant fraction of the atoms ... [more ▼]

We propose an experimental scheme which allows us to realized approximate time reversal of matter waves for ultracold atoms in the regime of quantum chaos. We show that a significant fraction of the atoms return back to their original state, being at the same time cooled down by several orders of magnitude. We give a theoretical description of this effect supported by extensive numerical simulations. The proposed scheme can be implemented with existing experimental setups. [less ▲]

Detailed reference viewed: 23 (8 ULg)
Full Text
Peer Reviewed
See detailDetuning effects in the vertical cold-atom micromaser
Martin, John ULg; Bastin, Thierry ULg

in European Physical Journal D -- Atoms, Molecules, Clusters & Optical Physics (2008), 48

The quantum theory of the cold atom micromaser including the effects of gravity is established in the general case where the cavity mode and the atomic transition frequencies are detuned.We show that ... [more ▼]

The quantum theory of the cold atom micromaser including the effects of gravity is established in the general case where the cavity mode and the atomic transition frequencies are detuned.We show that atoms which classically would not reach the interaction region are able to emit a photon inside the cavity. The system turns out to be extremely sensitive to the detuning and in particular to its sign. A method to solve the equations of motion for non resonant atom-field interaction and arbitrary cavity modes is presented. [less ▲]

Detailed reference viewed: 30 (13 ULg)
Full Text
Peer Reviewed
See detailCoherent control of atomic tunnelling
Martin, John ULg; Braun, Daniel

in Journal of Physics B Atomic Molecular Physics (2008), 41

We study the tunnelling of a two-level atom in a double well potential while the atom is coupled to a single electromagnetic field mode of a cavity. The coupling between internal and external degrees of ... [more ▼]

We study the tunnelling of a two-level atom in a double well potential while the atom is coupled to a single electromagnetic field mode of a cavity. The coupling between internal and external degrees of freedom, due to the mechanical effect on the atom from photon emission into the cavity mode, can dramatically change the tunnelling behaviour. We predict that in general the tunnelling process becomes quasiperiodic. In a certain regime of parameters a collapse and revival of the tunnelling occurs. Accessing the internal degrees of freedom of the atom with a laser allows us to coherently manipulate the atom position, and in particular to prepare the atom in one of the two wells. [less ▲]

Detailed reference viewed: 23 (7 ULg)
Full Text
Peer Reviewed
See detailTime Reversal of Bose-Einstein Condensates
Martin, John ULg; Georgeot, B.; Shepelyansky, D. L.

in Physical Review Letters (2008), 101

Using Gross-Pitaevskii equation, we study the time reversibility of Bose-Einstein condensates (BEC) in kicked optical lattices, showing that in the regime of quantum chaos, the dynamics can be inverted ... [more ▼]

Using Gross-Pitaevskii equation, we study the time reversibility of Bose-Einstein condensates (BEC) in kicked optical lattices, showing that in the regime of quantum chaos, the dynamics can be inverted from explosion to collapse. The accuracy of time reversal decreases with the increase of atom interactions in BEC, until it is completely lost. Surprisingly, quantum chaos helps to restore time reversibility. These predictions can be tested with existing experimental setups. [less ▲]

Detailed reference viewed: 33 (9 ULg)
See detailEntanglement of localized states
Martin, John ULg; Giraud, Olivier; Georgeot, Bertrand

Poster (2007, October)

Detailed reference viewed: 4 (0 ULg)
See detailEntanglement of localized states
Martin, John ULg; Giraud, Olivier; Georgeot, Bertrand

Conference (2007, June)

Detailed reference viewed: 4 (1 ULg)
Full Text
Peer Reviewed
See detailQuantum Imaging with Incoherent Photons
Thiel, C.; Bastin, Thierry ULg; Martin, John ULg et al

in Physical Review Letters (2007), 99

We propose a technique to obtain subwavelength resolution in quantum imaging with potentially 100% contrast using incoherent light. Our method requires neither path-entangled number states nor multiphoton ... [more ▼]

We propose a technique to obtain subwavelength resolution in quantum imaging with potentially 100% contrast using incoherent light. Our method requires neither path-entangled number states nor multiphoton absorption. The scheme makes use of N photons spontaneously emitted by N atoms and registered by N detectors. It is shown that for coincident detection at particular detector positions a resolution of lambda/N can be achieved. [less ▲]

Detailed reference viewed: 28 (5 ULg)
Full Text
Peer Reviewed
See detailCold three-level atom micromaser in the far-detuning regime
Martin, John ULg; Bastin, Thierry ULg

in Physical Review. A (2007), 75

We analyze the quantum theory of the two-mode micromaser pumped by cold three-level atoms with a Lambda-configuration under the two-photon resonance condition. We focus more specifically on the large ... [more ▼]

We analyze the quantum theory of the two-mode micromaser pumped by cold three-level atoms with a Lambda-configuration under the two-photon resonance condition. We focus more specifically on the large detuning limit where the detuning between the two cavity mode frequencies and the two atomic transition frequencies is large in comparison with the atom-cavity coupling constants. We show that this regime can mimic a virtual two-level atom micromaser without spontaneous emission where the cavity acts for the atoms as a potential barrier or a potential well (depending on the sign of the detuning) and a zero potential but no more both as a potential barrier and a potential well as it is the case for the usual cold two-level atom micromaser [M. O. Scully, G. M. Meyer, and H. Walther, Phys. Rev. Lett. 76, 4144 (1996)]. This introduces interesting options for engineering the interaction between the cold atoms and the cavity. The elimination of the spontaneous emission solves a major issue of the conventional cold two-level atom micromaser as the transit time of cold atoms inside and in the vicinity of the cavity is usually much larger than the atomic level lifetimes. It is also shown that the cold atom regime is very sensitive to the sign of the detuning (in contrast to the hot atom regime) and that, according to this sign, the cavity may speed up or slow down the incident three-level atoms after their interaction with the field. [less ▲]

Detailed reference viewed: 34 (11 ULg)
Full Text
Peer Reviewed
See detailEntanglement of localized states
Giraud, O.; Martin, John ULg; Georgeot, B.

in Physical Review. A (2007), 76

We derive exact expressions for the mean value of Meyer-Wallach entanglement Q for localized random vectors drawn from various ensembles corresponding to different physical situations. For vectors ... [more ▼]

We derive exact expressions for the mean value of Meyer-Wallach entanglement Q for localized random vectors drawn from various ensembles corresponding to different physical situations. For vectors localized on a randomly chosen subset of the basis, <Q> tends for large system sizes to a constant which depends on the participation ratio, whereas for vectors localized on adjacent basis states it goes to zero as a constant over the number of qubits. Applications to many-body systems and Anderson localization are discussed. [less ▲]

Detailed reference viewed: 21 (9 ULg)
See detailQuantum imaging with incoherent photons
Thiel, C.; Solano, E.; Bastin, Thierry ULg et al

Conference (2007)

Detailed reference viewed: 7 (4 ULg)
See detailLe micromaser à atomes froids
Martin, John ULg; Bastin, Thierry ULg

Scientific conference (2006, January)

Detailed reference viewed: 9 (2 ULg)
Full Text
Peer Reviewed
See detailQuantum theory of the cold-atom micromaser including gravity
Bastin, Thierry ULg; Martin, John ULg

in Physical Review. A (2005), 72

The quantum theory of the cold-atom micromaser including the effects of gravity is considered. We show that gravity does not break the special properties of the induced emission probability for the ... [more ▼]

The quantum theory of the cold-atom micromaser including the effects of gravity is considered. We show that gravity does not break the special properties of the induced emission probability for the micromaser in the cold atom regime and rather new effects are predicted. In particular, we show that the cavity acts in the gravity field as an additional repulsive and attractive potential, resulting in quasibound states of the atomic motion. This feature gives rise to fine resonances in the induced emission probability that are not restricted to any particular cavity mode function, in contrast to the usual cold-atom micromaser. It is also shown that the atom is able to emit a photon inside the cavity, though classically it does not reach the interaction region. Predictions about the photon number statistics when the cavity is pumped by a flux of excited atoms are finally given. Unusual highly nonclassical "dragon" distributions are still predicted in the vertical geometry. (c) 2005 American Institute of Physics. [less ▲]

Detailed reference viewed: 21 (8 ULg)
Full Text
Peer Reviewed
See detailReply to "Comment on 'Detuning effects in the one-photon mazer' "
Bastin, Thierry ULg; Martin, John ULg

in Physical Review. A (2004), 70

We refute in this Reply the criticisms made by Abdel-Aty. We show that none of them are founded and we demonstrate very explicitly what is wrong with the arguments developed by this author.

Detailed reference viewed: 47 (3 ULg)
Full Text
Peer Reviewed
See detailTransmission of ultracold atoms through a micromaser: detuning effects
Martin, John ULg; Bastin, Thierry ULg

in European Physical Journal D -- Atoms, Molecules, Clusters & Optical Physics (2004), 29

The transmission probability of ultracold atoms through a micromaser is studied in the general case where a detuning between the cavity mode and the atomic transition frequencies is present. We generalize ... [more ▼]

The transmission probability of ultracold atoms through a micromaser is studied in the general case where a detuning between the cavity mode and the atomic transition frequencies is present. We generalize previous results established in the resonant case (zero detuning) for the mesa mode function. In particular, it is shown that the velocity selection of cold atoms passing through the micromaser can be very easily tuned and enhanced using a non-resonant field inside the cavity. Also, the transmission probability exhibits with respect to the detuning very sharp resonances that could define single cavity devices for high accuracy metrology purposes (atomic clocks). [less ▲]

Detailed reference viewed: 22 (8 ULg)