PRA: Photon, electron, atom, and molecule interactions with solids and surfaces

Noninvasive electron microscopy with interaction-free quantum measurements

William P. Putnam and Mehmet Fatih Yanik — 2009-10-23T00:00:00-04:00

Author(s): William P. Putnam and Mehmet Fatih Yanik
We propose the use of interaction-free quantum measurements with electrons to eliminate sample damage in electron microscopy. This might allow noninvasive molecular-resolution imaging. We show the possibility of such measurements in the presence of experimentally measured quantum decoherence rates a...

[Phys. Rev. A 80, 040902] Published Fri Oct 23, 2009

Casimir-Polder forces on moving atoms

Stefan Scheel and Stefan Yoshi Buhmann — 2009-10-22T00:00:00-04:00

Author(s): Stefan Scheel and Stefan Yoshi Buhmann
Polarizable atoms and molecules experience the Casimir-Polder force near magnetoelectric bodies, a force that is induced by quantum fluctuations of the electromagnetic field and the matter. Atoms and molecules in relative motion to a magnetoelectric surface experience an additional velocity-dependen...
[Phys. Rev. A 80, 042902] Published Thu Oct 22, 2009

Electron emission spectra of thermal collisions of He metastable atoms with Au(111) and Pt(111) surfaces: Evidence for Penning ionization

S. Masuda, K. Sasaki, M. Sogo, M. Aoki, and Y. Morikawa — 2009-10-14T00:00:00-04:00

Author(s): S. Masuda, K. Sasaki, M. Sogo, M. Aoki, and Y. Morikawa
Electron emission spectra obtained by thermal collisions of He^{∗} (2 ^{1} S and 2 ^{3} S ) atoms with Au(111) and Pt(111) surfaces were measured to clarify the electronically excited atom-metal interactions. It has been recognized that the metastable atoms de-excite on ordinary noble- and transit...

[Phys. Rev. A 80, 040901] Published Wed Oct 14, 2009

Threshold effects in surface-plasmon transition rates and neutral fractions for protons traveling near a metallic surface

H. Jouin and F. A. Gutierrez — 2009-10-05T00:00:00-04:00

Author(s): H. Jouin and F. A. Gutierrez
In this work the ion’s velocity dependence of surface-plasmon-induced transition rates for proton neutralization at metal surfaces is analyzed. In particular we study the opening of the collective channel for the H^{+} -Al system, which is known to be closed in the fixed ion approximation. The thr...
[Phys. Rev. A 80, 042901] Published Mon Oct 05, 2009

Velocity dependence of the energy loss of very slow proton and deuteron beams in Cu and Ag

E. D. Cantero, G. H. Lantschner, J. C. Eckardt, and N. R. Arista — 2009-09-30T00:00:00-04:00

Author(s): E. D. Cantero, G. H. Lantschner, J. C. Eckardt, and N. R. Arista
We present energy loss measurements of protons and deuterons down to velocities of 0.1 a.u. in very thin polycrystalline Cu and Ag foils, using the transmission technique. As in previous experiments in Au, a transition between two energy loss regimes is observed, i.e., from a stopping due to the exc...
[Phys. Rev. A 80, 032904] Published Wed Sep 30, 2009

Statistical fluctuations in energy loss for swift heavy ions in thick polymeric foils

2009-09-24T00:00:00-04:00

Author(s): Pratibha K. Gulati, Neetu Munjal, P. K. Diwan, V. Sharma, S. Kumar, S. A. Khan, and D. K. Avasthi
The statistical fluctuations in energy loss have been measured for O, Si, and S ions, in varying thicknesses of polyethylene naphthalate [PEN, or (C_{7} H_{5} O_{2} ) ] polymeric foils. The measurements have been performed in the fractional energy-loss limits ΔE/E∼5–90 % . These fluctuations ...
[Phys. Rev. A 80, 032903] Published Thu Sep 24, 2009

Laser-assisted photoemission from adsorbate-covered metal surfaces: Time-resolved core-hole relaxation dynamics from sideband profiles

C.-H. Zhang and U. Thumm — 2009-09-21T00:00:00-04:00

Author(s): C.-H. Zhang and U. Thumm
Illumination of an adsorbate-covered metal surface with an xuv and a delayed ir laser pulse can result in sidebands in the photoelectron (PE) spectra. We present a theoretical model for the delay-dependent PE spectra and show how the relaxation dynamics of xuv-induced core-level holes in adsorbate a...
[Phys. Rev. A 80, 032902] Published Mon Sep 21, 2009

Casimir-Polder interaction between an atom and a dielectric slab

Ana María Contreras Reyes and Claudia Eberlein — 2009-09-16T00:00:00-04:00

Author(s): Ana María Contreras Reyes and Claudia Eberlein
We present an explicit analytic calculation of the energy-level shift of an atom in front of a nondispersive and nondissipative dielectric slab. We work with the fully quantized electromagnetic field, taking retardation into account. We give the shift as a two-dimensional integral and use asymptotic...
[Phys. Rev. A 80, 032901] Published Wed Sep 16, 2009

Secondary-electron cascade in attosecond photoelectron spectroscopy from metals

Jan Conrad Baggesen and Lars Bojer Madsen — 2009-09-16T00:00:00-04:00

Author(s): Jan Conrad Baggesen and Lars Bojer Madsen
Attosecond spectroscopy is currently restricted to photon energies around 100 eV. We show that under these conditions, electron-electron scatterings, as the photoelectrons leave the metal, give rise to a tail of secondary electrons with lower energies and hence a significant background. We develop a...

[Phys. Rev. A 80, 030901] Published Wed Sep 16, 2009

Channeling effect in electronic spectra produced by grazing impact of fast protons on insulator surfaces

C. D. Archubi and M. S. Gravielle — 2009-09-10T00:00:00-04:00

Author(s): C. D. Archubi and M. S. Gravielle
Electron emission due to grazing scattering of fast protons from LiF and KCl surfaces is studied under axial channeling conditions. The differential electron emission probability is calculated within a distorted-wave formalism, taking into account realistic channeled trajectories. For electronic spe...
[Phys. Rev. A 80, 034901] Published Thu Sep 10, 2009

Theory of Casimir-Polder forces

Bo-Sture Skagerstam, Per Kristian Rekdal, and Asle Heide Vaskinn — 2009-08-31T00:00:00-04:00

Author(s): Bo-Sture Skagerstam, Per Kristian Rekdal, and Asle Heide Vaskinn
We consider the energy shift for an atom close to a nonmagnetic body with a magnetic moment coupled to a quantized magnetic field. The corresponding repulsive Casimir-Polder force is obtained for a perfect conductor, a metal, a dielectric medium, with dielectric properties modeled by a Drude formula...
[Phys. Rev. A 80, 022902] Published Mon Aug 31, 2009

Enhancement of thermal Casimir-Polder potentials of ground-state polar molecules in a planar cavity

Simen Å. Ellingsen, Stefan Yoshi Buhmann, and Stefan Scheel — 2009-08-13T00:00:00-04:00

Author(s): Simen Å. Ellingsen, Stefan Yoshi Buhmann, and Stefan Scheel
We analyze the thermal Casimir-Polder potential experienced by a ground-state molecule in a planar cavity and investigate the prospects for using such a setup for molecular guiding. The resonant atom-field interaction associated with this nonequilibrium situation manifests itself in oscillating stan...
[Phys. Rev. A 80, 022901] Published Thu Aug 13, 2009

Light-induced atomic desorption dynamics: Theory for a completely illuminated cell

Krzysztof Rębilas — 2009-07-17T00:00:00-04:00

Author(s): Krzysztof Rębilas
The light-induced atomic desorption effect, known as LIAD, has been explained so far by a debatable Atutov’s theory [S. N. Atutov , Phys. Rev. A 60, 4693 (1999)]. In this Brief Report, we propose an approach in which the difficulties of this theory are removed. The theory yields predictions for th...
[Phys. Rev. A 80, 014901] Published Fri Jul 17, 2009

Energy loss of protons in W using fully relativistic calculations and mean excitation energies of W, Au, Pb, and Bi

C. C. Montanari, D. M. Mitnik, C. D. Archubi, and J. E. Miraglia — 2009-07-16T00:00:00-04:00

Author(s): C. C. Montanari, D. M. Mitnik, C. D. Archubi, and J. E. Miraglia
We present a theoretical study on the energy loss of protons in wolframium by calculating target fully relativistic wave functions and binding energies. The HULLAC code is employed to obtain numerical solutions of the Dirac equation. We use the shellwise local plasma approximation (SLPA) to evaluate...
[Phys. Rev. A 80, 012901] Published Thu Jul 16, 2009

Wake effects and energy loss for a charged particle moving above a thin metal film

Chun-Zhi Li, Yuan-Hong Song, and You-Nian Wang — 2009-06-24T00:00:00-04:00

Author(s): Chun-Zhi Li, Yuan-Hong Song, and You-Nian Wang
We consider a charged particle moving parallel to the surface of a metal film covering on the semi-infinite dielectric substrate with constant speed. By means of the linearized quantum hydrodynamic theory, the induced electron gas density and the stopping power are studied, taking into account the q...
[Phys. Rev. A 79, 062903] Published Wed Jun 24, 2009

Atomic multipole relaxation rates near surfaces

J. A. Crosse and Stefan Scheel — 2009-06-18T00:00:00-04:00

Author(s): J. A. Crosse and Stefan Scheel
The spontaneous relaxation rates for an atom in free space and close to an absorbing surface are calculated to various orders of the electromagnetic multipole expansion. The spontaneous decay rates for dipole, quadrupole, and octupole transitions are calculated in terms of their respective primitive...
[Phys. Rev. A 79, 062902] Published Thu Jun 18, 2009

Simulation of attosecond streaking of electrons emitted from a tungsten surface

C. Lemell, B. Solleder, K. Tőkési, and J. Burgdörfer — 2009-06-09T00:00:00-04:00

Author(s): C. Lemell, B. Solleder, K. Tőkési, and J. Burgdörfer
First time-resolved photoemission experiments employing attosecond streaking of electrons emitted by an extended ultraviolet pump pulse and probed by a few-cycle near-infrared pulse found a time delay of about 100 as between photoelectrons from the conduction band and those from the 4f core level of...
[Phys. Rev. A 79, 062901] Published Tue Jun 09, 2009

Orientation dependence of Casimir forces

T. Emig, N. Graham, R. L. Jaffe, and M. Kardar — 2009-05-14T00:00:00-04:00

Author(s): T. Emig, N. Graham, R. L. Jaffe, and M. Kardar
The Casimir interaction between two objects, or between an object and a plane, depends on their relative orientations. We make these angular dependences explicit by considering prolate or oblate spheroids. The variation with orientation is calculated exactly at asymptotically large distances for the...
[Phys. Rev. A 79, 054901] Published Thu May 14, 2009

Dynamics of thermal Casimir-Polder forces on polar molecules

Simen Ådnøy Ellingsen, Stefan Yoshi Buhmann, and Stefan Scheel — 2009-05-07T00:00:00-04:00

Author(s): Simen Ådnøy Ellingsen, Stefan Yoshi Buhmann, and Stefan Scheel
We study the influence of thermal Casimir-Polder forces on the near-surface trapping of cold polar molecules, with emphasis on LiH and YbF near a Au surface at room temperature. We show that even for a molecule initially prepared in its electronic and rovibrational ground state, the Casimir-Polder f...
[Phys. Rev. A 79, 052903] Published Thu May 07, 2009

Interaction of 18-keV O^{−} ions with Al_{2} O_{3} nanocapillaries

2009-05-05T00:00:00-04:00

Author(s): Guangzhi Sun, Ximeng Chen, Jun Wang, Yifeng Chen, Junkui Xu, Chunlin Zhou, Jianxiong Shao, Ying Cui, Baowei Ding, Yongzhi Yin, Xin’an Wang, Fengjun Lou, Xueyang Lv, Xiyu Qiu, Juanjuan Jia, Lin Chen, Fayuan Xi, Zichun Chen, Lanting Li, and Zhaoyuan Liu
The transmission of 18-keV O^{−} ions through Al_{2} O_{3} nanocapillaries with 50 nm in diameter and 12 μm in length is studied in this work. By measuring angular distribution of transmitted particles when capillaries were tilted with respect to incident ion beam, two peaks were observed. It i...
[Phys. Rev. A 79, 052902] Published Tue May 05, 2009

Classical and quantum analysis of quasiresonance in grazing atom-surface collisions

Antonia Ruiz, José P. Palao, and Eric J. Heller — 2009-05-04T00:00:00-04:00

Author(s): Antonia Ruiz, José P. Palao, and Eric J. Heller
Quasiresonance is a general effect that may arise from the coupling between approximately resonant degrees of freedom in a system perturbed by some transient interaction. In a process induced by a slowly switching on and off of the coupling interaction, quasiresonance is characterized by the existen...
[Phys. Rev. A 79, 052901] Published Mon May 04, 2009

Impact of magnetic properties on atom-wall interactions

G. Bimonte, G. L. Klimchitskaya, and V. M. Mostepanenko — 2009-04-24T00:00:00-04:00

Author(s): G. Bimonte, G. L. Klimchitskaya, and V. M. Mostepanenko
Lifshitz-type formulas for the free energy and Casimir-Polder force between an atom possessing a permanent magnetic moment and a wall made of different materials are derived. A simple model allowing analytical results is considered where the atomic magnetic susceptibility is frequency independent an...
[Phys. Rev. A 79, 042906] Published Fri Apr 24, 2009

Modification of glass cell walls by rubidium vapor

J. Ma, A. Kishinevski, Y.-Y. Jau, C. Reuter, and W. Happer — 2009-04-23T00:00:00-04:00

Author(s): J. Ma, A. Kishinevski, Y.-Y. Jau, C. Reuter, and W. Happer
It has long been known that the inner walls of freshly manufactured glass cells filled with a few droplets of alkali metal undergo a “curing” process, where the properties of the cell wall change over a period of days to weeks. We report quantitative studies of “curing” in Pyrex cells filled...
[Phys. Rev. A 79, 042905] Published Thu Apr 23, 2009

Experimental and theoretical study of the energy loss of Be and B ions in Zn

2009-04-23T00:00:00-04:00

Author(s): E. D. Cantero, R. C. Fadanelli, C. C. Montanari, M. Behar, J. C. Eckardt, G. H. Lantschner, J. E. Miraglia, and N. R. Arista
Energy-loss measurements and theoretical calculations for Be and B ions in Zn are presented. The experimental ion energies range from 40 keV/u to 1 MeV/u, which includes the energy-loss maximum and covers a lack of experimental data for these systems from intermediate to high energies. The measureme...
[Phys. Rev. A 79, 042904] Published Thu Apr 23, 2009

Reexamination of the theory of light-induced atomic desorption

Krzysztof Rębilas and Marek J. Kasprowicz — 2009-04-17T00:00:00-04:00

Author(s): Krzysztof Rębilas and Marek J. Kasprowicz
The commonly accepted theory of light-induced atomic desorption (LIAD) [S. N. Atutov , Phys. Rev. A 60, 4693 (1999)] explains the dynamics of this effect by referring to a light-enhanced diffusion process proceeding in the absorbing medium. On the other hand, recently performed measurements show tha...
[Phys. Rev. A 79, 042903] Published Fri Apr 17, 2009

Guided transmission of Ne^{7+} ions through nanocapillaries in insulating polymers: Scaling laws for projectile energies up to 50 keV

2009-04-17T00:00:00-04:00

Author(s): N. Stolterfoht, R. Hellhammer, Z. Juhász, B. Sulik, V. Bayer, C. Trautmann, E. Bodewits, A. J. de Nijs, H. M. Dang, and R. Hoekstra
The guiding of multiply charged Ne^{7+} ions through nanocapillaries in highly insulating polymers was investigated. Highly parallel capillaries with a density of ≲10^{7} cm^{−2} and diameters of ≲100 nm were utilized. The widths of the angular profiles were measured for Ne^{7+} ions tran...
[Phys. Rev. A 79, 042902] Published Fri Apr 17, 2009

Stopping power of antiprotons in H, H_{2} , and He targets

Armin Lühr and Alejandro Saenz — 2009-04-16T00:00:00-04:00

Author(s): Armin Lühr and Alejandro Saenz
The stopping power of antiprotons in atomic and molecular hydrogen as well as helium was calculated in an impact-energy range from 1 keV to 6.4 MeV. In the case of H_{2} and He the targets were described with a single-active electron model centered on the target. The collision process was treated wi...
[Phys. Rev. A 79, 042901] Published Thu Apr 16, 2009

Energy loss of protons in Au, Pb, and Bi using relativistic wave functions

C. C. Montanari, C. D. Archubi, D. M. Mitnik, and J. E. Miraglia — 2009-03-31T00:00:00-04:00

Author(s): C. C. Montanari, C. D. Archubi, D. M. Mitnik, and J. E. Miraglia
We present a theoretical study on proton energy loss in solid targets of atomic number greater than 54. Fully relativistic wave functions and binding energies are obtained by solving numerically the Dirac equation. Ab initio calculations are developed for the first (stopping) and second (straggling)...
[Phys. Rev. A 79, 032903] Published Tue Mar 31, 2009

Ultrafast studies of electronic processes at surfaces using the laser-assisted photoelectric effect with long-wavelength dressing light

2009-03-30T00:00:00-04:00

Author(s): L. Miaja-Avila, J. Yin, S. Backus, G. Saathoff, M. Aeschlimann, M. M. Murnane, and H. C. Kapteyn
We show that ultrafast surface science studies using the laser-assisted photoelectric effect can benefit from longer-wavelength infrared dressing beams. We compare soft-x-ray photoemission from a Pt(111) surface dressed by 1300 and 780 nm light. Using 1300 nm light, the amplitude of the laser-assist...

[Phys. Rev. A 79, 030901] Published Mon Mar 30, 2009

Modification of energy shifts of atoms by the presence of a boundary in a thermal bath and the Casimir-Polder force

Zhiying Zhu and Hongwei Yu — 2009-03-09T00:00:00-04:00

Author(s): Zhiying Zhu and Hongwei Yu
We study the modification by the presence of a plane wall of energy-level shifts of two-level atoms which are in multipolar coupling with quantized electromagnetic fields in a thermal bath in a formalism which separates the contributions of thermal fluctuations and radiation reaction and allows a di...
[Phys. Rev. A 79, 032902] Published Mon Mar 09, 2009