Mark Tame

1. Quantum Information Processing with Surface Plasmons Mark Tame Coworkers: Changhyoup Lee, Jinhyoung Lee, Daniel Ballester, Mauro Paternostro, Anatoly Zayats and Myungshik Kim QTeQ - Quantum Technology at Queen’s Queen’s University, Belfast [11th April, 2008]

2. Overview Introduction - What are Surface Plasmons? Applications - Nano-plasmonics and QIP Current Achievements - Studies related to QIP Problems to be Solved

3. Overview Introduction - What are Surface Plasmons? Applications - Nano-plasmonics and QIP Current Achievements - Studies related to QIP Problems to be Solved

4. Introduction – a Brief History Robert Wood observes power loss in a spectroscopy experiment for light reflected off metal grating surfaces 1902 Jonathan Zenneck unknowingly introduces mathematical description of surface plasma waves, while studying radio waves. 1907 Ugo Fano produces the first consistent explanation of Wood’s observed power loss: surface plasma waves are properly introduced. 1947 -1956: David Pines introduces quantized plasma oscillations in bulk metals, calling them “plasmons”. -1957: Rufus Ritchie studies electron energy losses in thin films: first theoretical description of surface plasmons. -1958: John Hopfield introduces the term “polariton” for the coupled oscillation of bound electrons and light in transparent media. 1956- 1958 1968 Andreas Otto, Erich Kretschmann and Heinz Raether present methods for the optical excitation of surface plasmon polaritons on metal films. This is a major advancement, making experiments on surface plasmon polaritons easily accessible to many researchers (see bar chart). 2002 The quantum optics and quantum information communities begin to develop a keen interest in using surface plasmon polaritons for QIP purposes… Now

5. Introduction – What are Surface Plasmons? Photon SPP Barnes, Dereux and Ebbesen, Nature 824, 242 (2003) (for air eair=1) Johnson and Christy, PRB 6, 4370 (1972)

6. Introduction – What are Surface Plasmons? Q: What’s the difference between a surface plasmon and a surface plasmon polariton? Photon “curve” SPP “curve” Plasmon like: (hydrodynamics important) Photon like: (retardation important) l

7. Introduction – Length scales Highly confined dm – decay of SPP into metal dd – decay of SPP into air/dielectric l – a chosen wavelength for the SPP dSP – propagation decay length of SPP

8. Introduction – excitation methods Otto (1968) Kretschmann-Raether (1968) Zayats, Smolyaninov and Maradudin, Phys. Rep. 408, 131 (2005) SNOM (1989) Diffraction grating (1974) Mode-matching possible:

9. Introduction – other modes in a metal TO Bulk Photon curve LO Bulk Plasmon curve -Surface phonon polaritons -Bulk phonon polaritons Elson and Ritchie, PRB 4, 4129 (1971)

10. Introduction – quantization Surface plasma waves Quantize Surface plasmon polaritons 1stretarded quantization: Elson and Ritchie, PRB 4, 4129 (1971)

11. Overview Introduction - What are Surface Plasmons? Applications - Nano-plasmonics and QIP Current Achievements - Studies related to QIP Problems to be Solved

12. Applications General: • Electrochemistry • -Knoll, Ann. Rev. Phys. Chem 49, 569 (1998) • Biosensing • -Malmqvist, Nature 361, 186 (1993) • Scanning tunneling microscopy • -Berndt et al., PRL 67, 3796 (1991) • Miniature photonic circuits (sub-wavelength) • -Nomura et al., APL 86, 181108

13. Applications QIP: Due to tight field confinement, non-linear effects can be significantly larger than standard fibre-based solutions Quantum Computing: • Non-linear sign gate required in KLM scheme, • -Knill, Laflamme and Milburn, Nature 409, 46 (1998) • Single qubit rotations in coherent state QIP, • -Jeong and Kim, PRA 65, 042305 (2002) • -Enk and Hirota, PRA 64, 022313 (2001) • -Ralph, Munro and Milburn, quant-ph/0110115 QIP in general: • Generating optical coherent cat states, • -Yurke and Stoler, PRL 57, 13 (1986) • Complete set of Bell discriminators (i.e. full • Bell measurement) • -Lutkenhaus, Calsamiglia and Suominen, PRA 59, 3295 (1999) • Photon blockade • -Imamoglu, PRL (2001), Paternostro, Kim and Ham, JMO (2003) • Various schemes based on EIT • -Imamoglu, Beausoleil, Paternostro, Petrosyan, Ottaviani... • Single photon transistor, • -Chang et al., Nature Physics 3, 807 (2007)

14. Overview Introduction - What are Surface Plasmons? Applications - Nano-plasmonics and QIP Current Achievements - Studies related to QIP Problems to be Solved

15. Current Achievements Nature 418, 304 (2002) Theory: Moreno et al. PRL 92, 236801 (2004)

16. Current Achievements Fasel et al. PRL 94, 110501 (2005) Theory: Fasel et al. NJP 8, 13 (2006)

17. Current Achievements Akimov et al. Nature 450, 402 (2007) Theory: Akimov et al. PRL 97, 053002 (2006)

18. Current Achievements Theory: Chang et al. Nature Physics 3, 807 (2007) Coupling method:

19. Overview Introduction - What are Surface Plasmons? Applications - Nano-plasmonics and QIP Current Achievements - Studies related to QIP Problems to be Solved

20. Problems to be solved • Reaching higher transfer efficiencies (in/out) in experiments • (max 27% - Akimov et al. Nature 450, 402 (2007)) • Satisfactory theory of Photon-SPP coupling • at the quantum level • Understanding nonlinear SPP effects and how to • take advantage

21. Overview Introduction - What are Surface Plasmons? Applications - Nano-plasmonics and QIP Current Achievements - Studies related to QIP Problems to be Solved