Comptes Rendus
Nanophotonics and near field / Nanophotonique et champ proche
High-resolution microscopy of plasmon field distributions by scanning tunneling luminescence and photoemission electron microscopies
[Microscopie à haute résolution des champs plasmoniques par microscopie tunnel à balayage de sonde et par microscopie de photoémission multiphotonique]
Comptes Rendus. Physique, Volume 13 (2012) no. 8, pp. 815-829.

Lʼexploitation des résonances plasmons dans le but de promouvoir lʼinteraction entre des molécules conjuguées et des champs optiques motive actuellement dʼintenses recherches. Les objectifs en sont la compréhension du rôle médiateur des interactions optiques joué par les modes de plasmon et la réalisation de nanostructures métalliques avec une précision moléculaire voire atomique, combinant les effets dʼexaltation de champ et dʼantennes optiques. Dans cet article de synthèse, nous présentons des exemples de cartographie des champs plasmoniques basés sur deux techniques de microscopie : lʼémission de lumière induite par microscopie tunnel à balayage de sonde (scanning tunneling microscopy — STM) et lʼimagerie de photoémission multiphotonique (photoemission electron microscopy — PEEM), deux techniques parmi celles qui offrent aujourdʼhui les meilleures résolutions spatiales pour la microscopie plasmonique. Une propriété peu conventionnelle de la jonction du microscope à effet tunnel est sa capacité à se comporter comme une source localisée de lumière. Celle-ci peut être exploitée pour sonder localement les propriétés opto-électroniques en surface, en particulier les modes plasmoniques, avec une résolution spatiale inférieure au nanomètre. Lʼavantage de cette résolution ultime est cependant contrebalancé par la nécessité dʼune déconvolution parfois délicate de lʼinfluence de la sonde. Alternativement, les inconvénients inhérents aux techniques de sondes locales peuvent être surmontés par lʼimagerie des électrons photoémis, en utilisant les méthodes bien établies dʼoptique électronique. Ceci permet lʼobtention de cartes dʼintensité en deux dimensions reflétant directement la distribution non perturbée du champ proche optique. Cette approche fournit des images avec une résolution spatiale de lʼordre de 20 nm en routine et pouvant atteindre 5 nm avec les instruments les plus récents, incluant un dispositif de correction des aberrations.

The exploitation of plasmon resonances to promote the interaction between conjugated molecules and optical fields motivates intensive research. The objectives are to understand the mechanisms of plasmon-mediated interactions, and to realize molecularly- or atomically-precise metal nanostructures, combining field enhancements and optical antenna effects. In this review paper, we present examples of plasmonic-field mappings based on scanning tunneling microscope (STM)-induced light emission or multiphoton photoemission (PEEM), two techniques among those which offer todayʼs best spatial resolutions for plasmon microscopy. An unfamiliar property of the junction of an STM is its ability to behave as a highly localized source of light. It can be exploited to probe optoelectronic properties, in particular plasmonic fields, with ultimate subnanometer spatial resolution, an advantage balanced by a sometimes delicate deconvolution of local-probe influence. Alternatively, local-probe disadvantages can be overcome by imaging the photoemitted electrons, using well-established electron optics. This allows obtaining two-dimensional intensity maps reflecting the unperturbed distribution of the optical near field. This approach provides full field spectroscopic images with a routine spatial resolution of the order of 20 nm (down to 5 nm with recent aberration corrected instruments).

Publié le :
DOI : 10.1016/j.crhy.2012.10.001
Keywords: STM, PEEM, Subnanometer spatial resolution
Mot clés : Microscopie tunnel à balayage de sonde, Imagerie de photoémission multiphotonique, Résolution spatiale inférieure au nanomètre
Ludovic Douillard 1 ; Fabrice Charra 1

1 CEA-Saclay, service de physique et chimie des surfaces et interfaces, IRAMIS, 91191 Gif-sur-Yvette cedex, France
@article{CRPHYS_2012__13_8_815_0,
     author = {Ludovic Douillard and Fabrice Charra},
     title = {High-resolution microscopy of plasmon field distributions by scanning tunneling luminescence and photoemission electron microscopies},
     journal = {Comptes Rendus. Physique},
     pages = {815--829},
     publisher = {Elsevier},
     volume = {13},
     number = {8},
     year = {2012},
     doi = {10.1016/j.crhy.2012.10.001},
     language = {en},
}
TY  - JOUR
AU  - Ludovic Douillard
AU  - Fabrice Charra
TI  - High-resolution microscopy of plasmon field distributions by scanning tunneling luminescence and photoemission electron microscopies
JO  - Comptes Rendus. Physique
PY  - 2012
SP  - 815
EP  - 829
VL  - 13
IS  - 8
PB  - Elsevier
DO  - 10.1016/j.crhy.2012.10.001
LA  - en
ID  - CRPHYS_2012__13_8_815_0
ER  - 
%0 Journal Article
%A Ludovic Douillard
%A Fabrice Charra
%T High-resolution microscopy of plasmon field distributions by scanning tunneling luminescence and photoemission electron microscopies
%J Comptes Rendus. Physique
%D 2012
%P 815-829
%V 13
%N 8
%I Elsevier
%R 10.1016/j.crhy.2012.10.001
%G en
%F CRPHYS_2012__13_8_815_0
Ludovic Douillard; Fabrice Charra. High-resolution microscopy of plasmon field distributions by scanning tunneling luminescence and photoemission electron microscopies. Comptes Rendus. Physique, Volume 13 (2012) no. 8, pp. 815-829. doi : 10.1016/j.crhy.2012.10.001. https://comptes-rendus.academie-sciences.fr/physique/articles/10.1016/j.crhy.2012.10.001/

[1] M. Faraday Philosophical Transactions of the Royal Society, 145 (1857)

[2] E.M. Purcell Physical Review, 69 (1946), p. 681

[3] M. Moskovits Reviews of Modern Physics, 57 (1985), p. 783

[4] P.E. Batson Ultramicroscopy, 9 (1982), p. 277

[5] F. Hache; D. Ricard; C. Flytzanis Journal of the Optical Society of America B — Optical Physics, 3 (1986), p. 1647

[6] T.W. Ebbesen; H.J. Lezec; H.F. Ghaemi; T. Thio; P.A. Wolff Nature, 391 (1998), p. 667

[7] A. Lewis; M. Isaacson; A. Harootunian; A. Muray Ultramicroscopy, 13 (1984), p. 227

[8] D.W. Pohl; W. Denk; M. Lanz Applied Physics Letters, 44 (1984), p. 651

[9] R.M. Tromp Ultramicroscopy, 111 (2011), p. 273

[10] R.W. Wood Philosophical Magazine, 4 (1902), p. 396

[11] A. Otto Physica Status Solidi, 26 (1968), p. K99

[12] E. Kretschmann; H. Raether Zeitschrift für Naturforschung, Teil A — Astrophysik, Physik und Physikalische Chemie, 23 (1968), p. 2135

[13] A. Garcia-Etxarri; I. Romero; F.J.G. de Abajo; R. Hillenbrand; J. Aizpurua Physical Review B, 79 (2009), p. 5

[14] A.V. Zayats; I.I. Smolyaninov Journal of Optics A — Pure and Applied Optics, 5 (2003), p. S16

[15] P. Ghenuche; S. Cherukulappurath; T.H. Taminiau; N.F. van Hulst; R. Quidant Physical Review Letters, 101 (2008), p. 4

[16] M. Sandtke; L. Kuipers Nature Photonics, 1 (2007), p. 573

[17] R.M. Bakker; A. Boltasseva; Z.T. Liu; R.H. Pedersen; S. Gresillon; A.V. Kildishev; V.P. Drachev; V.M. Shalaev Optics Express, 15 (2007), p. 13682

[18] M. Rang; A.C. Jones; F. Zhou; Z.Y. Li; B.J. Wiley; Y.N. Xia; M.B. Raschke Nano Letters, 8 (2008), p. 3357

[19] J. Nelayah; M. Kociak; O. Stephan; F.J.G. de Abajo; M. Tence; L. Henrard; D. Taverna; I. Pastoriza-Santos; L.M. Liz-Marzan; C. Colliex Nature Physics, 3 (2007), p. 348

[20] E.J.R. Vesseur; R.D. Waele; M. Kuttge; A. Polman Nano Letters, 7 (2007), p. 2843

[21] A.L. Koh; K. Bao; I. Khan; W.E. Smith; G. Kothleitner; P. Nordlander; S.A. Maier; D.W. McComb ACS Nano, 3 (2009), p. 3015

[22] U. Hohenester; H. Ditlbacher; J.R. Krenn Physical Review Letters, 103 (2009), p. 4

[23] F.J.G. de Abajo; M. Kociak Physical Review Letters, 100 (2008), p. 4

[24] A.G. Bell American Journal of Sciences, XX (1880), p. 305

[25] T. Inagaki; Y. Nakagawa; E.T. Arakawa; D.J. Aas Physical Review B, 26 (1982), p. 6421

[26] B. Rothenhausler; J. Rabe; P. Korpiun; W. Knoll Surface Science, 137 (1984), p. 373

[27] S. Negm; H. Talaat Journal of Physics — Condensed Matter, 1 (1989), p. 10201

[28] R.J. Matelon; D.M. Newman; M.L. Wears Review of Scientific Instruments, 75 (2004), p. 2560

[29] L. Tong; Q.S. Wei; A. Wei; J.X. Cheng Photochemistry and Photobiology, 85 (2009), p. 21

[30] R. Vogelgesang; A. Dmitriev Analyst, 135 (2010), p. 1175

[31] J.K. Gimzewski; J.K. Sass; R.R. Schlitter; J. Schott Europhysics Letters, 8 (1989), p. 435

[32] R. Berndt; R. Gaisch; J.K. Gimzewski; B. Reihl; R.R. Schlittler; W.D. Schneider; M. Tschudy Science, 262 (1993), p. 1425

[33] M.M.J. Bischoff; M. van der Wielen; H. van Kempen Surface Science, 400 (1998), p. 127

[34] K. Ito; S. Ohyama; Y. Uehara; S. Ushioda Surface Science, 324 (1995), p. 282

[35] P. Dumas; C. Syrykh; V. Makarenko; F. Salvan Europhysics Letters, 40 (1997), p. 447

[36] R. Loudon The Quantum Theory of Light, Oxford University Press, Oxford, 2003

[37] K. Perronet; L. Barbier; F. Charra Physical Review B, 70 (2004), p. 201405(R)

[38] R. Berndt; R. Gaisch; W.D. Schneider; J.K. Gimzewski; B. Reihl; R.R. Schlittler; M. Tschudy Physical Review Letters, 74 (1995), p. 102

[39] E.M. Purcell Physical Review, 69 (1946), p. 681

[40] P. Meystre; M.I. Sargent Elements of Quantum Optics, Springer, Berlin, 2007

[41] R. Carminati; J.J. Greffet; C. Henkel; J.M. Vigoureux Optics Communications, 261 (2006), p. 368

[42] M.R. Philpott Journal of Chemical Physics, 62 (1975), p. 1812

[43] S.C. Ching; H.M. Lai; K. Young Journal of the Optical Society of America B — Optical Physics, 4 (1987), p. 2004

[44] G. Sun; J.B. Khurgin; R.A. Soref Applied Physics Letters, 94 (2009), p. 101103

[45] D. Hone; B. Muhlschlegel; D.J. Scalapino Applied Physics Letters, 33 (1978), p. 203

[46] L.C. Davis Physical Review B, 16 (1977), p. 2482

[47] J.R. Kirtley; T.N. Theis; J.C. Tsang; D.J. Dimaria Physical Review B, 27 (1983), p. 4601

[48] B.N.J. Persson; A. Baratoff Physical Review Letters, 68 (1992), p. 3224

[49] R.W. Rendell; D.J. Scalapino; B. Muhlschlegel Physical Review Letters, 41 (1978), p. 1746

[50] P. Johansson; R. Monreal; P. Apell Physical Review B, 42 (1990), p. 9210

[51] Y. Uehara, Y. Kimura, S. Ushioda, K. Takeuchi, Japanese Journal of Applied Physics, Part 1 — Regular Papers, Short Notes & Review Papers 31 (1992) 2465.

[52] J. Aizpurua; S.P. Apell; R. Berndt Physical Review B, 62 (2000), p. 2065

[53] H.X. Xu; J. Aizpurua; M. Kall; P. Apell Physical Review E, 62 (2000), p. 4318

[54] A.G. Malshukov Physics Reports — Review Section of Physics Letters, 194 (1990), p. 343

[55] P. Andre; F. Charra; M. Pileni Journal of Applied Physics, 91 (2002), p. 3028

[56] R.W. Rendell; D.J. Scalapino; B. Muhlschlegel Physical Review Letters, 41 (1978), p. 1746

[57] M. Schmeits; L. Dambly Physical Review B, 44 (1991), p. 12706

[58] L. Khriachtchev; L. Heikkila; T. Kuusela Applied Physics Letters, 78 (2001), p. 1994

[59] J.I. Gonzalez; T.H. Lee; M.D. Barnes; Y. Antoku; R.M. Dickson Physical Review Letters, 93 (2004), p. 147402

[60] S.A. Nepijko; R.D. Fedorovich; L.V. Viduta; D.N. Ievlev; W. Schulze Annalen der Physik, 9 (2000), p. 125

[61] J. Lambe; S.L. McCarthy Physical Review Letters, 37 (1976), p. 923

[62] K. Kuhnke; A. Kabakchiev; W. Stiepany; F. Zinser; R. Vogelgesang; K. Kern Review of Scientific Instruments, 81 (2010), p. 113102

[63] K. Kusova; F. Charra; G. Schull; I. Pelant Surface Science, 602 (2008), p. 345

[64] K. Perronet; F. Charra Physical Review B, 67 (2003), p. 153402

[65] F. Charra Nanocrystals Forming Mesoscopic Structures (M.-P. Pileni, ed.), Wiley–VCH Verlag GmbH & Co. KGaA, Weinheim, Germany, 2005, p. 231

[66] H.J. Mamin; P.H. Guethner; D. Rugar Physical Review Letters, 65 (1990), p. 2418

[67] A. Taleb; C. Petit; M.P. Pileni Chemistry of Materials, 9 (1997), p. 950

[68] P.J. Durston; J. Schmidt; R.E. Palmer; J.P. Wilcoxon Applied Physics Letters, 71 (1997), p. 2940

[69] F. Silly; A.O. Gusev; A. Taleb; F. Charra; M.P. Pileni Physical Review Letters, 84 (2000), p. 5840

[70] A.O. Gusev; A. Taleb; F. Silly; F. Charra; M.P. Pileni Advanced Materials, 12 (2000), p. 663

[71] A. Taleb; F. Silly; A.O. Gusev; F. Charra; M.P. Pileni Advanced Materials, 12 (2000), p. 1583

[72] A. Taleb; V. Russier; A. Courty; M.P. Pileni Physical Review B, 59 (1999), p. 13350

[73] P. Myrach; N. Nilius; H.J. Freund Physical Review B, 83 (2011), p. 35416

[74] T. Wang; E. Boer-Duchemin; Y. Zhang; G. Comtet; G. Dujardin Nanotechnology, 22 (2011), p. 175201

[75] A. Bouhelier; T. Huser; H. Tamaru; H.J. Guntherodt; D.W. Pohl; F.I. Baida; D. Van Labeke Physical Review B, 63 (2001), p. 155404

[76] T.A. Callcott; E.T. Arakawa Physical Review B, 11 (1975), p. 2750

[77] H.L. Skriver; N.M. Rosengaard Physical Review B, 46 (1992), p. 7157

[78] J. Bosenberg Physics Letters A, 37 (1971), p. 439

[79] F. Sabary; J.C. Dudek Vacuum, 41 (1990), p. 476

[80] E.L. Nolle; M.Y. Schelev Technical Physics, 50 (2005), p. 1528

[81] P. Monchicourt; M. Raynaud; H. Saringar; J. Kupersztych Journal of Physics — Condensed Matter, 9 (1997), p. 5765

[82] M. Munzinger; C. Wiemann; M. Rohmer; L. Guo; M. Aeschlimann; M. Bauer New Journal of Physics, 7 (2005), p. 68

[83] S.I. Anisimov; V.A. Benderskii; G. Farkas Soviet Physics — Uspekhi, 20 (1977), p. 467

[84] J.H. Bechtel; W.L. Smith; N. Bloembergen Physical Review B, 15 (1977), p. 4557

[85] R. Yen; J.M. Liu; N. Bloembergen; T.K. Yee; J.G. Fujimoto; M.M. Salour Applied Physics Letters, 40 (1982), p. 185

[86] R.T. Williams; T.R. Royt; J.C. Rife; J.P. Long; M.N. Kabler Journal of Vacuum Science & Technology, 21 (1982), p. 509

[87] A. Gloskovskii; D. Valdaitsev; S.A. Nepijko; G. Schonhense; B. Rethfeld Surface Science, 601 (2007), p. 4706

[88] P. Dombi Advances in Imaging and Electron Physics, vol. 158, Elsevier Academic Press Inc., San Diego, 2009 (p. 1)

[89] W. Pfeiffer; C. Kennerknecht; M. Merschdorf Applied Physics A — Materials Science & Processing, 78 (2004), p. 1011

[90] J.G. Endriz; W.E. Spicer Physical Review Letters, 27 (1971), p. 570

[91] H.W. Rudolf; W. Steinmann Physics Letters A, 61 (1977), p. 471

[92] U. Even; K.A. Holcomb; C.W. Snyder; P.R. Antoniewicz; J.C. Thompson Surface Science, 165 (1986), p. L35

[93] T. Tsang; T. Srinivasanrao; J. Fischer Physical Review B, 43 (1991), p. 8870

[94] N. Aeschlimann; C.A. Schmuttenmaer; H.E. Elsayed-Ali; R.J.D. Miller; J. Cao; Y. Gao; D.A. Mantell Journal of Chemical Physics, 102 (1995), p. 8606

[95] J. Lehmann; M. Merschdorf; W. Pfeiffer; A. Thon; S. Voll; G. Gerber Physical Review Letters, 85 (2000), p. 2921

[96] J. Kupersztych; P. Monchicourt; M. Raynaud Physical Review Letters, 86 (2001), p. 5180

[97] M. Maillard; P. Monchicourt; M.P. Pileni Chemical Physics Letters, 380 (2003), p. 704

[98] G. Banfi; G. Ferrini; M. Peloi; F. Parmigiani Physical Review B — Condensed Matter and Materials Physics, 67 (2003), p. 10

[99] C. Wiemann; D. Bayer; M. Rohmer; M. Aeschlimann; M. Bauer Surface Science, 601 (2007), p. 4714

[100] W. Driesel, H. Bethge, in: Proc. Conf. on Energy-Pulse Modification of Semiconductors and Related Materials II, 1985.

[101] E. Bauer Journal of Physics — Condensed Matter, 21 (2009), p. 10

[102] E. Bauer; M. Mundschau; W. Swiech; W. Telieps Ultramicroscopy, 31 (1989), p. 49

[103] W. Swiech; G.H. Fecher; C. Ziethen; O. Schmidt; G. Schonhense; K. Grzelakowski; C.M. Schneider; R. Fromter; H.P. Oepen; J. Kirschner Journal of Electron Spectroscopy and Related Phenomena, 84 (1997), p. 171

[104] S. Gunther; B. Kaulich; L. Gregoratti; M. Kiskinova Progress in Surface Science, 70 (2002), p. 187

[105] A. Locatelli; E. Bauer Journal of Physics — Condensed Matter, 20 (2008), p. 22

[106] S. Nettesheim; A. Vonoertzen; H.H. Rotermund; G. Ertl Journal of Chemical Physics, 98 (1993), p. 9977

[107] H.H. Rotermund; S. Nettesheim; A. Vonoertzen; G. Ertl Surface Science, 275 (1992), p. L645

[108] F. Heringdorf; M.C. Reuter; R.M. Tromp Nature, 412 (2001), p. 517

[109] R. Gerlach; T. Maroutian; L. Douillard; D. Martinotti; H.J. Ernst Surface Science, 480 (2001), p. 97

[110] G. Schonhense Journal of Physics — Condensed Matter, 11 (1999), p. 9517

[111] G.A. Massey; M.D. Jones; J.C. Johnson IEEE Journal of Quantum Electronics, 17 (1981), p. 1035

[112] O. Schmidt; G.H. Fecher; Y. Hwu; G. Schonhense Surface Science, 482 (2001), p. 687

[113] M. Cinchetti; A. Gloskovskii; S.A. Nepjiko; G. Schonhense; H. Rochholz; M. Kreiter Physical Review Letters, 95 (2005), p. 47601

[114] A. Kubo; K. Onda; H. Petek; Z.J. Sun; Y.S. Jung; H.K. Kim Nano Letters, 5 (2005), p. 1123

[115] A. Kubo; Y.S. Jung; H.K. Kim; H. Petek Journal of Physics B — Atomic, Molecular and Optical Physics, 40 (2007) (S259)

[116] M. Aeschlimann; M. Bauer; D. Bayer; T. Brixner; F.J. de Abajo; W. Pfeiffer; M. Rohmer; C. Spindler; F. Steeb Nature, 446 (2007), p. 301

[117] L.I. Chelaru; M. Horn-von Hoegen; D. Thien; F.J.M. zu Heringdorf Physical Review B, 73 (2006), p. 5

[118] L.I. Chelaru; F. Heringdorf Surface Science, 601 (2007), p. 4541

[119] C. Hrelescu; T.K. Sau; A.L. Rogach; F. Jackel; G. Laurent; L. Douillard; F. Charra Nano Letters, 11 (2011), p. 402

[120] L. Douillard; F. Charra; C. Fiorini; P.M. Adam; R. Bachelot; S. Kostcheev; G. Lerondel; M.L. de la Chapelle; P. Royer Journal of Applied Physics, 101 (2007), p. 83518

[121] L. Douillard; F. Charra; Z. Korczak; R. Bachelot; S. Kostcheev; G. Lerondel; P.M. Adam; P. Royer Nano Letters, 8 (2008), p. 935

[122] M.I. Stockman; M.F. Kling; U. Kleineberg; F. Krausz Nature Photonics, 1 (2007), p. 539

[123] S.J. Peppernick; A.G. Joly; K.M. Beck; W.P. Hess Journal of Chemical Physics, 134 (2011), p. 7

[124] R.C. Word; T. Dornan; R. Konenkamp Applied Physics Letters, 96 (2010), p. 3

[125] C. Awada; T. Popescu; L. Douillard; F. Charra; A. Perron; H. Yockell-Lelievre; A.L. Baudrion; P.M. Adam; R. Bachelot Journal of Physical Chemistry C, 116 (2012), p. 14591

[126] C. Hrelescu; T.K. Sau; A.L. Rogach; F. Jackel; J. Feldmann Applied Physics Letters, 94 (2009), p. 3

[127] F. Hao; C.L. Nehl; J.H. Hafner; P. Nordlander Nano Letters, 7 (2007), p. 729

[128] H.S. Lee; C. Awada; S. Boutami; F. Charra; L. Douillard; R.E. de Lamaestre Optics Express, 20 (2012), p. 8974

[129] L.X. Zhang; A. Kubo; L.M. Wang; H. Petek; T. Seideman Physical Review B, 84 (2011), p. 245442

[130] C. Lemke; T. Leissner; S. Jauernik; A. Klick; J. Fiutowski; J. Kjelstrup-Hansen; H.G. Rubahn; M. Bauer Optics Express, 20 (2012), p. 12877

[131] P. Melchior; D. Bayer; C. Schneider; A. Fischer; M. Rohmer; W. Pfeiffer; M. Aeschlimann Physical Review B, 83 (2011), p. 235407

[132] M. Aeschlimann; M. Bauer; D. Bayer; T. Brixner; S. Cunovic; A. Fischer; P. Melchior; W. Pfeiffer; M. Rohmer; C. Schneider; C. Struber; P. Tuchscherer; D.V. Voronine New Journal of Physics, 14 (2012), p. 33030

[133] T. Brixner; F.J.G. de Abajo; J. Schneider; C. Spindler; W. Pfeiffer Physical Review B, 73 (2006), p. 125437

[134] P. Tuchscherer; C. Rewitz; D.V. Voronine; F.J.G. de Abajo; W. Pfeiffer; T. Brixner Optics Express, 17 (2009), p. 14235

[135] F. Silly; F. Charra Applied Physics Letters, 77 (2000), p. 3648

[136] K. Perronet; G. Schull; P. Raimond; F. Charra Europhysics Letters, 74 (2006), p. 313

Cité par Sources :

Commentaires - Politique


Ces articles pourraient vous intéresser

Luminescence induced by a scanning-tunneling microscope as a nanophotonic probe

Fabien Silly; Fabrice Charra

C. R. Phys (2002)


Seeing and measuring in colours: Electron microscopy and spectroscopies applied to nano-optics

Mathieu Kociak; Odile Stéphan; Alexandre Gloter; ...

C. R. Phys (2014)