Surface ionisation of molecular H<sub>2</sub> and atomic H Rydberg states at doped silicon surfaces

Sashikesh, G.; So, E.; Ford, Mark S.; Softley, T. P.

doi:10.1080/00268976.2014.940022

Cited by 7 publications

(7 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Experimental studies have been primarily conducted with flat-metal surfaces for which the ionization dynamics are almost independent of the material because of the generic behavior of RCT to the conduction band. However, there have also been some experimental and/or theoretical investigations of the effects of adlayers and thin insulating films [5], interaction with doped semiconductor surfaces [6] and dielectric materials [7], effects of corrugation and of patch charges [8,9]. Related theoretical calculations were used to investigate the variation of ionization rate of ground state Hwith the thickness of a metal film substrate [10].…”

mentioning

confidence: 99%

Resonant Charge Transfer of Hydrogen Rydberg Atoms Incident on a Cu(100) Projected Band-Gap Surface

et al. 2015

Self Cite

View full text Add to dashboard Cite

The charge transfer (ionization) of hydrogen Rydberg atoms (n = 25 − 34) at a Cu(100) surface is investigated. Unlike fully metallic surfaces, where the Rydberg electron energy is degenerate with the conduction band of the metal, the Cu(100) surface has a projected bandgap at these energies, and only discrete image states are available through which charge transfer can take place. Resonant enhancement of charge transfer is observed for Rydberg states whose energy matches one of the image states, and the integrated surface ionization signals (signal versus applied field) show clear periodicity as a function of n as the energies come in and out of resonance with the image states. The surface ionization dynamics show a velocity dependence; decreased velocity of the incident H atom leads to a greater mean distance of ionization and a lower field required to extract the ion. The surface-ionization profiles for 'on resonance' n values show a changing shape as the velocity is changed, reflecting the finite field range over which resonance occurs.The collision of a Rydberg atom in the gas phase with a solid surface typically leads to transfer of the Rydberg electron to the surface at distances less than 5n 2 a 0 , where n is the Rydberg electron principal quantum number. This is especially true for metallic surfaces, where the Rydberg electron energy is degenerate with the conduction band so that resonant charge transfer (RCT) can occur. Experimental and theoretical studies of this phenomenon have focused on the effects of varying the n quantum number, the parabolic quantum number k, the velocity of the incoming particle and the applied fields [1,2], and observing how the rate of ionization varies as a function of distance from the surface [3]. For nonhydrogenic atoms, adiabatic and non-adiabatic passage through surface-induced energy level crossings leads to behavior that varies with the Rydberg species [4]. Thus, such studies reveal important information about the Rydberg states and their dynamics near surfaces.An equally important question for such studies is what they reveal about the nature of the surface. Experimental studies have been primarily conducted with flat-metal surfaces for which the ionization dynamics are almost independent of the material because of the generic behavior of RCT to the conduction band. However, there have also been some experimental and/or theoretical investigations of the effects of adlayers and thin insulating films [5], interaction with doped semiconductor surfaces [6] and dielectric materials [7], effects of corrugation and of patch charges [8,9]. Related theoretical calculations were used to investigate the variation of ionization rate of ground state H -with the thickness of a metal film substrate [10]. All these studies point to a degree of sensitivity of the charge transfer process to the surface characteristics. The mean radius of a hydrogenic Rydberg orbit is of order n 2 a 0 (e.g., ∼ 20 nm for n = 20) and charge transfer typically occurs at a Rydberg-surface distance of 3 − 5...

show abstract

mentioning

confidence: 99%

Resonant Charge Transfer of Hydrogen Rydberg Atoms Incident on a Cu(100) Projected Band-Gap Surface

et al. 2015

Self Cite

View full text Add to dashboard Cite

show abstract

“…During his seven years as Chair, Tim provided a steady guiding hand as the journal embarked on a range of new initiatives, including the Topical Reviews series, the annual Longuet-Higgins Young Author Prize [6], the New Views series [7], and the introduction of graphical abstracts. In addition, Tim has overseen numerous special issues (including several issues on high-resolution molecular spectroscopy [8][9][10]), and has continued to contribute articles as a co-author [11][12][13][14][15][16]. We wish Professor Softley well for the future and every success in his role as Pro-Vice-Chancellor for Research and Knowledge Transfer at the University of Birmingham, and we hope he will continue his association with the journal through future decades.…”

Section: Appointment Of New Chair Of Editors and New Editors From Chimentioning

confidence: 98%

Appointment of new chair of editors and new editors from China and Switzerland

2016

Molecular Physics

View full text Add to dashboard Cite

“…In this case the characteristics of the electron transfer process are dominated by the properties of the Rydberg state (principal quantum number n and parabolic quantum number k) and the experimental conditions (applied field and Rydberg atom collisional velocity) [2][3][4][5] . However other studies using projected band gap surfaces 6,7 , doped silicon surfaces 8 , insulating thin films 9 , dielectric materials 10 and adlayers indicate that the surface ionization of a Rydberg atom can also be used to learn about the geometrical or electronic structure of the surface.…”

Section: Introductionmentioning

confidence: 99%

Handshake electron transfer from hydrogen Rydberg atoms incident at a series of metallic thin films

Gibbard

Softley

2016

The Journal of Chemical Physics

View full text Add to dashboard Cite

Thin metallic films have a 1D quantum well along the surface normal direction, which yields particle-in-a-box style electronic quantum states. However the quantum well is not infinitely deep and the wavefunctions of these states penetrate outside the surface where the electron is bound by its own image-charge attraction. Therefore a series of discrete, vacant states reach out from the thin film into the vacuum increasing the probability of electron transfer from an external atom or molecule to the thin film, especially for the resonant case where the quantum well energy matches that of the Rydberg atom. We show that 'handshake' electron transfer from a highly excited Rydberg atom to these thin-film states is experimentally measurable. Thicker films, have a wider 1D box, changing the energetic distribution and image-state contribution to the thin film wavefunctions, resulting in more resonances. Calculations successfully predict the number of resonances and the nature of the thin-film wavefunctions for a given film thickness.

show abstract

Surface ionisation of molecular H₂ and atomic H Rydberg states at doped silicon surfaces

Cited by 7 publications

References 40 publications

Resonant Charge Transfer of Hydrogen Rydberg Atoms Incident on a Cu(100) Projected Band-Gap Surface

Resonant Charge Transfer of Hydrogen Rydberg Atoms Incident on a Cu(100) Projected Band-Gap Surface

Appointment of new chair of editors and new editors from China and Switzerland

Handshake electron transfer from hydrogen Rydberg atoms incident at a series of metallic thin films

Contact Info

Product

Resources

About

Surface ionisation of molecular H2 and atomic H Rydberg states at doped silicon surfaces

Cited by 7 publications

References 40 publications

Resonant Charge Transfer of Hydrogen Rydberg Atoms Incident on a Cu(100) Projected Band-Gap Surface

Resonant Charge Transfer of Hydrogen Rydberg Atoms Incident on a Cu(100) Projected Band-Gap Surface

Appointment of new chair of editors and new editors from China and Switzerland

Handshake electron transfer from hydrogen Rydberg atoms incident at a series of metallic thin films

Contact Info

Product

Resources

About

Surface ionisation of molecular H₂ and atomic H Rydberg states at doped silicon surfaces