# Publications

**Recent Publications**

**Resonant squeezing and the anharmonic decay of coherent phonons**

S. Fahy, É. D. Murray, and D. A. Reis

Phys. Rev. B **93**, 134308 (2016)

**Broadband phonon scattering in PbTe-based materials driven near ferroelectric phase transition by strain or alloying**

R. M. Murphy, É. D. Murray, S. Fahy, and I. Savić

Phys. Rev. B **93**, 104304 (2016)

**Heterogeneously-Grown Tunable Tensile Strained Germanium on Silicon for Photonic Devices**

M. Clavel, D. Saladukha, P. S. Goley, T. J. Ochalski, F. Murphy-Armando, R. J. Bodnar, M. K. Hudait

Appl. Mater. Interfaces (2015)

**First-principles calculation of femtosecond symmetry-breaking atomic forces in photoexcited bismuth**

É. D. Murray and S. Fahy

Physical Review Letters **114**, 055502 (2015)

**Optimized Laser Thermal Annealing on Germanium for High Dopant Activation and Low Leakage Current**

M. Shayesteh, D.O. Connell, F. Gity, P. Murphy-Armando, R. Yu, K. Huet, I. Toque-Tresonne, F. Cristiano, S. Boninelli, H.H. Henrichsen, P.F. Nielsen, D.H. Petersen, R. Duffy,

IEEE Transactions on Electron Devices , (2014)

**Vibrational mode frequencies of H2S and H2O adsorbed on Ge(0 0 1)-(2 × 1) surfaces**

M. C. Hartnett and S. Fahy

Applied Surface Science , (2014)

**Self-consistent Green’s function method for dilute nitride conduction band structure**

M. Seifikar, E. P. O'Reilly, S. Fahy

Journal of Physics: Condensed Matter , 365502 (2014)

**Optical absorption of dilute nitride alloys using self-consistent Green’s function method**

M. Seifikar, E. P. O'Reilly, S. Fahy

Nanoscale Research Letters **9**, 51 (2014)

**Fourier-transform inelastic X-ray scattering from time and momentum-dependent phonon–phonon correlations**

M. Trigo, M. Fuchs, J. Chen, M. P. Jiang, M. Cammarata, S. Fahy, D. M. Fritz, K. Gaffney, S. Ghimire, A. Higginbotham, S. L. Johnson, M. E. Kozina, J. Larsson, H. Lemke, A. M. Lindenberg, G. Ndabashimiye, F. Quirin, K. Sokolowski-Tinten, C. Uher, G. Wang, J. S. Wark, D. Zhu, D. A. Reis

Nature Physics **9**, 790-794 (2013)

**Time- and momentum-resolved probe of heat transport in photo-excited bismuth **

J. Chen, M. Trigo, S. Fahy, É. D. Murray, Y. M. Sheu, T. Graber, R. Henning, Y. J. Chien, C. Uher and D. A. Reis,

Appl. Phys. Lett. **103**, 181903 (2013)

**Free-carrier relaxation and lattice heating in photoexcited bismuth **

Y. M. Sheu, Y. J. Chien, C. Uher, S. Fahy, and D. A. Reis

Phys. Rev. B **87**, 075429 (2013)

**Optical Probing of Ultrafast Electronic Decay in Bi and Sb with Slow Phonons **

J. J. Li, J. Chen, D. A. Reis, S. Fahy, and R. Merlin

Phys. Rev. Lett.**110**, 047401 (2013)

**Giant piezoresistance in silicon-germanium alloys **

F. Murphy-Armando and S. Fahy

Phys. Rev. B **86**, 035205 (2012)

**First-principles investigation of the alloy scattering potential in dilute Si1-xCx **

M. P. Vaughan, F. Murphy-Armando, and S. Fahy

Phys. Rev. B **85**, 165209 (2012)

**Giant mobility enhancement in highly strained, direct gap Ge**

F. Murphy-Armando and S. Fahy,

Ultimate Integration on Silicon (ULIS), 2011 12th Int. Conf. on, DOI:10.1109/ULIS.2011.5757987, (2011)

**Alloy scattering of substitutional carbon in silicon: A first principles approach**

M. P. Vaughan, F. Murphy-Armando and S. Fahy,

Ultimate Integration on Silicon (ULIS), 2011 12th Int. Conf. on, DOI:10.1109/ULIS.2011.5757983, (2011)

**Analysis of band-anticrossing model in GaNAs near localised states**

M. Seifikar, E.P. O'Reilly and S. Fahy,

Phys. Status Solidi B, **248**, 1176 (2011)

**Modelling and direct measurement of the density of states in GaAsN**

M.P. Vaughan, S. Fahy, E.P. O'Reilly, L. Ivanova, H. Eisele and M. Däe,

Phys. Status Solidi B, **248**, 1167 (2011)

**Vibrational signature of the Si-N defect in Si-doped GaN _{x}As_{1-x}**

J. Buckeridge, S. O'Halloran, S. Fahy,

Solid State Commun.

**150**, 1967 (2010)

**Journal Publications**

**Time- and momentum-resolved probe of heat transport in photo-excited bismuth **

J. Chen, M. Trigo, S. Fahy, É. D. Murray, Y. M. Sheu, T. Graber, R. Henning, Y. J. Chien, C. Uher and D. A. Reis,

Appl. Phys. Lett. **103**, 181903 (2013)

**Free-carrier relaxation and lattice heating in photoexcited bismuth **

Y. M. Sheu, Y. J. Chien, C. Uher, S. Fahy, and D. A. Reis

Phys. Rev. B **87**, 075429 (2013)

**Optical Probing of Ultrafast Electronic Decay in Bi and Sb with Slow Phonons **

J. J. Li, J. Chen, D. A. Reis, S. Fahy, and R. Merlin

Phys. Rev. Lett.**110**, 047401 (2013)

**Giant piezoresistance in silicon-germanium alloys **

F. Murphy-Armando and S. Fahy

Phys. Rev. B **86**, 035205 (2012)

**First-principles investigation of the alloy scattering potential in dilute Si1-xCx **

M. P. Vaughan, F. Murphy-Armando, and S. Fahy

Phys. Rev. B **85**, 165209 (2012)

**Analysis of band-anticrossing model in GaNAs near localised states**

M. Seifikar, E.P. O'Reilly and S. Fahy,

Phys. Status Solidi B, **248**, 1176 (2011)

**Modelling and direct measurement of the density of states in GaAsN**

M.P. Vaughan, S. Fahy, E.P. O'Reilly, L. Ivanova, H. Eisele and M. Däe,

Phys. Status Solidi B, **248**, 1167 (2011)

**Vibrational signature of the Si-N defect in Si-doped GaN _{x}As_{1-x}**

J. Buckeridge, S. O'Halloran, S. Fahy,

Solid State Commun.

**150**, 1967 (2010)

**Direct measurement and analysis of the conduction band density of states in diluted GaAs _{1-x}N_{x} alloys**

L. Ivanova, H. Eisele, M. P. Vaughan, Ph. Ebert, A. Lenz, R. Timm, O. Schumann, L. Geelhaar, M. Dahne, S. Fahy, H. Riechert, and E. P. O' Reilly,

Phys. Rev. B

**82**, 161201(R) (2010)

**Nitrogen composition dependence of electron effective mass in GaAs _{1-x}N_{x}**

T. Dannecker, Y. Jin, H. Cheng, C. F. Gorman, J. Buckeridge, C. Uher, S. Fahy, C. Kurdak and R.S. Goldman,

Phys. Rev. B

**82**, 125203 (2010)

**Non-equilibrium phonon dynamics studied by grazing-incidence femtosecond X-ray crystallography**

S. L. Johnson, P. Beaud, E. Vorobeva, C. J. Milne, É. D. Murray, S. Fahy and G. Ingold,

Acta Crystallogr. A **66**, 157-167 (2010)

**Comment on ''Directly Observing Squeezed Phonon States with Femtosecond X-Ray Diffraction'' Reply**

S. L. Johnson, P. Beaud, E. Vorobeva, C. J. Milne, É. D. Murray, S. Fahy and G. Ingold,

Phys. Rev. Lett. **104**, 029602 (2010)

**Optical transitions in dilute GaN _{x}As_{1-x} nitrides: A comparison between ab initio and empirical pseudopotentials**

G. Stenuit and S. Fahy,

J. Phys. Chem. Solids

**70**, 769-777 (2009)

**Observation of Insulating Nanoislands in Ferromagnetic GaMnAs**

D. M. Wang, Y. H. Ren, P. W. Jacobs, S. Fahy, X. Liu, J. K. Furdyna, V. F. Sapega and R. Merlin,

Phys. Rev. Lett. **102**, 256401 (2009)

**Directly Observing Squeezed Phonon States with Femtosecond X-Ray Diffraction**

S. L. Johnson, P. Beaud, E. Vorobeva, C. J. Milne, É. D. Murray, S. Fahy and G. Ingold,

Phys. Rev. Lett. **102**, 175503 (2009)

**Vibrational mode shifts as a measure of local strain in the dilute nitride semiconductor alloy GaN _{x}As_{1-x}**

J. Buckeridge, A. M. Teweldeberhan and S. Fahy,

Phys. Rev. B

**79**, 153201 (2009)

**First-principles calculation of carrier-phonon scattering in n-type Si _{1-x}Ge_{x} alloys**

F. Murphy-Armando and S. Fahy,

Phys. Rev. B

**78**, 035202 (2008)

**Effect of nitrogen interactions on photoluminescence linewidth broadening in dilute nitride semiconductors**

I. Bosa, D. McPeake and S. Fahy,

Phys. Rev. B **78**, 245206 (2008)

**Resonant Raman-active localized vibrational modes in Al _{y}Ga_{1-y}N_{x}As_{1-x} alloys: Experiment and first-principles calculations**

A. M. Teweldeberhan, G. Stenuit, S. Fahy, et al

Phys. Rev. B

**77**, 155208 (2008)

**Phonon spectra of the high-frequency modes in dilute nitride random GaN _{x}As_{1-x} alloy**

A. M. Teweldeberhan and S. Fahy,

Phys. Rev. B

**77**, 235216 (2008)

**Resonant Raman study of local vibration modes in AlGaAsN layers**

E. Gallardo, S. Lazic, J. M. Calleja, J. Miguel-Sanchez, M. Montes, A. Hierro, R. Gargallo-Caballero, A. Guzman, E. Munoz, A. M. Teweldeberhan and S. Fahy,

Physica E **40**, 2084-2086 (2008)

**Phonon dispersion relations and softening in photoexcited bismuth from first principles**

É. D. Murray, S. Fahy, D. Prendergast, T. Ogitsu, D. M. Fritz and D. A. Reis,

Phys. Rev. B **75**, 184301 (2007)

**Ultrafast bond softening in bismuth: Mapping a solid's interatomic potential with X-rays**

D. M. Fritz, D. A. Reis, B. Adams, R. A. Akre, J. Arthur, C. Blome, P. H. Bucksbaum, A. L. Cavalieri, S. Engemann, S. Fahy, et al,

Science **315**, 633-636 (2007)

**First-principles calculation of p-type alloy scattering in Si _{1-x}Ge_{x}**

S. Joyce, F. Murphy-Armando, and S. Fahy,

Phys. Rev. B

**75**, 155201 (2007)

**First-principles calculations of the mechanical and structural properties of GaN _{x}As_{1-x}: Lattice and elastic constants**

G. Stenuit and S. Fahy,

Phys. Rev. B

**76**, 035201 (2007)

**First-principles calculation of alloy scattering in Ge _{x}Si_{1-x}**

F. Murphy-Armando and S. Fahy,

Phys. Rev. Lett.

**97**, 096606 (2006)

**Simulations of time-resolved x-ray diffraction in Laue geometry**

B. Lings, J. S. Wark, M. F. DeCamp, D. A. Reis and S. Fahy,

J. Phys.: Condens. Matter **18**, 9231-9244 (2006)

**Novel Structural Features of CDK Inhibition Revealed by an ab Initio Computational Method Combined with Dynamic Simulations**

Lucy Heady, Marivi Fernandez-Serra, Ricardo L. Mancera, Sian Joyce, Ashok R. Venkitaraman, Emilio Artacho, Chris-Kriton Skylaris, Lucio Colombi Ciacchi, and Mike C. Payne,

J. Med. Chem. **49**, 5141-5153 (2006)

**Assigning carbon-13 NMR spectra to crystal structures by the INADEQUATE pulse sequence and first principles computation: a case study of two forms of testosterone**

Robin K. Harris, Sian A. Joyce, Chris J. Pickard, Sylvian Cadars and Lyndon Emsley,

Phys. Chem. Chem. Phys. **8**, 137 - 143 (2006)

**Alloy scattering of n-type carriers in GaN _{x}As_{1-x} **

S. Fahy, A. Lindsay, H. Ouerdane, and E. P. O'Reilly,

Phys. Rev. B

**74**, 035203 (2006)

**Effect of indium-nitrogen bonding on the localized vibrational mode in In _{y}Ga_{1-y}N_{x}As_{1-x}**

A. M. Teweldeberhan and S. Fahy,

Phys. Rev. B

**73**, 245215 (2006)

**Effect of lattice anharmonicity on high-amplitude phonon dynamics in photoexcited bismuth**

É D. Murray, D. M. Fritz, J. K. Wahlstrand, S. Fahy, and D. A. Reis,

Phys. Rev. B **72**, 060301 (2005)

**Calculated pressure dependence of the localized vibrational mode of nitrogen in GaN _{x}As_{1-x}**

A. M. Teweldeberhan and S. Fahy,

Phys. Rev. B

**72**, 195203 (2005)

**Theory of electron mobility in dilute nitride semiconductors**

S. Fahy and E.P. O'Reilly,

Physica E **21**, 881-885 (2004)

**Detection of Rabi oscillations in a two-dimensional electron gas under ultrafast intersubband excitation**

D. McPeake, F.T. Vasko and E.P. O'Reilly,

Semicond. Sci. Technol. **19**, S279-S281 (2004)

**Coherent Phonons: electronic softening or anharmonicity?**

S. Fahy and D. A. Reis,

Phys. Rev. Lett. **93**, 109701 (2004)

**Intrinsic limits on electron mobility in disordered dilute niride semiconductor alloys**

S. Fahy, A. Lindsay and E. P. O'Reilly,

IEE Proc., Optoelectron. **151**, 352 (2004)

**Theory of the electronic structure of dilute nitride alloys:beyond the band-anti-crossing model.**

E. P. O'Reilly, A. Lindsay and S. Fahy,

J. Phys.:Condens. Matter **16**, S3257-S3276 (2004).

**Transient strain driven by a dense electron-hole plasma**

M. F. deCamp, D. A. Reis, A. Cavalieri, P. H. Bucksbaum, R. Clarke, R. Merlin, E. M. Dufresne, D. A. Arms. A. Lindenberg, A. MacPhee, Z. Chang, B. Lings, J. S. Wark, and S. Fahy,

Phys. Rev. Lett. **91**, 165502 (2003)

**Intrinsic Limits on Electron Mobility in Dilute Nitride Semiconductors**

S. Fahy and E. P. O'Reilly,

Appl. Phys. Lett. **83**, 3731-3733 (2003)

**Book Chapters**

**Hot Electron Transport**

M. P. Vaughan,

Semiconductor Modeling Techniques

Springer Series in Materials Science **159**

Springer Berlin Heidelberg (2012)

**Tight-binding and k.p theory of dilute nitride alloys**

E.P. O'Reilly, A. Lindsay and S. Fahy,

Physics and applications of dilute nitrides, ch. 3,

Optoelectronic properties of semiconductors and superlattices, Vol. 21,

Ed. Irina A. Buyanova and Weimin M. Chen,

Taylor & Francis Books Inc., New York (2004)

**Conference Publications**

**Invited Talks**

**Quasi-localized states, electron scattering and carrier mobility in GaNAs**,

S.B. Fahy,

APS March Meeting 2005, Los Angeles, USA.

**Vortex matter and temperature dependence of the Ginzburg-Landau phenomenological lengths in lead nanowires**,

G. Stenuit , S. Michotte, J. Govaerts and L. Piraux,

to be published in the NATO Science Series

Proceedings of the NATO Advanced Research Workshop Electron Correlations in New Materials and Nanosystems,

Yalta (Ukraine), September 19-23, 2005).

**Energy minimization methods for Jastrow-Slater wavefunctions**,

S. Fahy,

Workshop on Electronic Structure beyond Density Functional Theory,

July 2004 at Lorentz Center, Leiden, Holland.

**The electronic structure of dilute nitride alloys: how robust is the band anti-crossing model?**,

E.P. O'Reilly, A. Lindsay and S. Fahy,

The 20th General Conference of the Condensed Matter Division, European Physical Society, Prague, July 19-23, 2004

**Contributed Papers**

**Giant mobility enhancement in highly strained, direct gap Ge**

F. Murphy-Armando and S. Fahy,

Ultimate Integration on Silicon (ULIS), 2011 12th Int. Conf. on, DOI:10.1109/ULIS.2011.5757987, (2011)

**Alloy scattering of substitutional carbon in silicon: A first principles approach**

M. P. Vaughan, F. Murphy-Armando and S. Fahy,

Ultimate Integration on Silicon (ULIS), 2011 12th Int. Conf. on, DOI:10.1109/ULIS.2011.5757983, (2011)

**First principles calculations of the scattering cross section of substitutional carbon in silicon**

M P Vaughan and S Fahy,

J. Phys.: Conf. Ser., **242**, 012003, (2010)

**Calculation of the Phonon Lifetime of Photoexcited Bismuth**,

É. D. Murray and S. Fahy,

APS March Meeting, 2006, Baltimore, MD

**Electronic transport in dilute GaAs:N**,

G. Stenuit and S. Fahy,

APS March Meeting, 2006, Baltimore, MD

**First-principles calculation of phonon scattering of n-type carriers in SiGe alloys**,

F. Murphy Armando and S. Fahy,

APS March Meeting, 2006, Baltimore, MD

**Mobility in SiGe alloys from first principles**,

S. Joyce and S. Fahy,

APS March Meeting, 2006, Baltimore, MD

**Low temperature photoluminescence in the strongly disordered dilute nitride GaAsN**,

I. Bosa, D. Mc Peake and S. Fahy,

APS March Meeting, 2006, Baltimore, MD

**Effect of indium on the localized vibrational mode of nitrogen in GaN _{x}As_{1-x.} **,

A. M. Teweldeberhan and S. Fahy,

APS March Meeting, 2006, Baltimore, MD

**Theory Of Electron Effective Mass And Mobility in Dilute Nitride Alloys**

A. Lindsay, S. Fahy and E.P. O'Reilly,

AIP Conf. Proc. **772**, 277 (2005)

**Localization and exciton line-width broadening in the dilute nitride, GaNAs**,

D. Mc Peake, I. Bosa, A. Lindsay, S. Fahy, E. P. O'Reilly,

APS March Meeting 2005, Los Angeles, USA

**Calculation of phonon dispersion relations and softening in photo-excited bismuth**,

É. D. Murray and S, Fahy

APS March Meeting 2005, Los Angeles, USA

**First-principles calculation of alloy scattering of n-type carriers in SiGe**,

F.Murphy-Amando and S.Fahy,

APS March Meeting 2005, Los Angeles, USA

**Velocity dependence of friction during relative sliding motion of finite concentric carbon nanotubes**,

P, Tangney, S. Fahy, M.L. Cohen and S.G. Louie,

APS March Meeting 2005, Los Angeles, USA

**Calculation of temperature dependence of electron mobility in dilute nitride alloys**,

S. Fahy, E. P. O'Reilly and A. Lindsay,

APS March Meeting 2004, Montreal

**Ultrafast x-ray study of electron-hole plasma diffusion,**,

D. Reis, P. Bucksbaum, A. Cavalieri, R. Clarke, M. DeCamp, E. Dufresne, R. Merlin, D. Arms, A. Lindenberg, A. MacPhee, Z. Chang, B. Lings, J. Wark and S. Fahy

APS March Meeting 2004, Montreal

**Calculation of coherent phonon frequency and amplitude in photo-excited bismuth,**,

É. D. Murray and S. Fahy

APS March Meeting 2004, Montreal

**Theory of exciton linewidth broadening and reduced mobility in GaNAs alloys**,

D. Mc Peake, I. Bosa, A. Lindsay, S. Fahy, E. P. O'Reilly,

MSS12 Albuquerque NM, 2005.

**Calculation of coherent phonon frequency and amplitude in photo-excited bismuth**,

É. D. Murray, S. Fahy and D. A. Reis,

(poster presentation)

Ultra-fast X-ray Conference, April 2004, San Diego.

**Intrinsic limits on electron mobility in disordered dilute nitride semiconductor alloys**,

S. Fahy, A. Lindsay and E. P. O'Reilly,

European Materials Research Society (E-MRS), Spring Meeting 2004, Strasbourg, May 2004.

**Calculation of coherent phonon frequency and amplitude in photo-excited bismuth**,

É. D. Murray and S. Fahy,

Flagstaff, Arizona, July 26-30, 2004.

**Temperature dependence of electron mobility in dilute nitride semiconductors**,

S. Fahy, E. P. O'Reilly and A. Lindsay,

International Conference on the Physics of Semiconductors. July 2004. Flagstaff, USA.

**Intrinsic limits on electron mobility in dilute nitride semiconductors**,

S. Fahy and E.P. O'Reilly,

IoP Condensed Matter and Material Physics (CMMP) Conference, 6-9 April 2003, Belfast, UK.

**Theory of electronic structure and gain properties of GaInNAs**,

E.P. O'Reilly, S. Fahy, A. Lindsay and S. Tomic,

International Workshop on GaAs-based lasers for 1.3 - 1.5 m m wavelength range, 24-26 April 2003, Wroclaw University of Technology, Poland.

**Theory of Electron Mobility in Dilute Nitride Semiconductors**,

S. Fahy and E.P. O'Reilly,

The 11th International Conference on Modulated Semiconductor Structures (MSS11), 14-18 July 2003, Nara, Japan.