Integrated optical components for quantum key distribution

The security of current public key cryptosystems, such as RSA, depends on the difficulty of computing certain functions known as trapdoor functions. However, as computational resources become more abundant with the fast development of super- and quantum computers, relying on such methods for communication security becomes risky. Quantum key distribution (QKD), is a potential solution that can allow theoretically secure key exchange for future communications. Chip-scale integration of this solution for securing communication of embedded systems and hand held devices demands miniaturizing the optical components that are used in typical QKD boxes, hence reducing its size and cost. The aim of the work in this thesis is firstly investigating novel approaches to realising integrable single photon sources and detectors for applications such as QKD, and secondly proposing a chip-scale integrated QKD system with efficient and optimised optical components. In the first part of the thesis, a model for coupling 2D material emitters to rod-type photonic cavities is studied for room temperature single photon sources. Our investigated approach allows better coupling between the emitter and the cavity modes than conventional methods, while increasing light collection ratio. In the second part, site-controlled growth of semiconductor III-V nanowires on Si for photodetection applications is achieved by fabricating the sites using electron-beam lithography and wet etching. Studies were also carried out to investigate the effect of the wafer’s growth temperature on the nanowire formation. Finally, a model was proposed for realising a chip-scale QKD system using photonic crystals as a photonic circuit platform. The work involves increasing the Q-factor of the cavity single photon source, increasing cavity waveguide coupling, reducing losses in beam splitters and out-couplers. A final model of a chip-scale QKD system which involves the optimised components is proposed at the end of the thesis.

[1]  E. Costard,et al.  Photonic band gaps and holography , 1997 .

[2]  Christopher B. Murray,et al.  Synthesis and Characterization of Monodisperse Nanocrystals and Close-Packed Nanocrystal Assemblies , 2000 .

[3]  Steven G. Johnson,et al.  Guided modes in photonic crystal slabs , 1999 .

[4]  Christopher J. Brennan,et al.  A review on mechanics and mechanical properties of 2D materials—Graphene and beyond , 2016, 1611.01555.

[5]  Jian-Wei Pan,et al.  On-Demand Single Photons with High Extraction Efficiency and Near-Unity Indistinguishability from a Resonantly Driven Quantum Dot in a Micropillar. , 2016, Physical review letters.

[6]  T. Asano,et al.  High-Q photonic nanocavity in a two-dimensional photonic crystal , 2003, Nature.

[7]  Arka Majumdar,et al.  Monolayer semiconductor nanocavity lasers with ultralow thresholds , 2015, Nature.

[8]  Yoshimasa Sugimoto,et al.  Low propagation loss of 0.76 dB/mm in GaAs-based single-line-defect two-dimensional photonic crystal slab waveguides up to 1 cm in length. , 2004, Optics express.

[9]  L. Seravalli,et al.  Molecular Beam Epitaxy: An Overview , 2011 .

[10]  M. Notomi,et al.  Extremely large group-velocity dispersion of line-defect waveguides in photonic crystal slabs. , 2001, Physical review letters.

[11]  Xiaocheng Jiang,et al.  InAs/InP radial nanowire heterostructures as high electron mobility devices. , 2007, Nano letters.

[12]  M. Guina,et al.  Structural Investigation of Uniform Ensembles of Self-Catalyzed GaAs Nanowires Fabricated by a Lithography-Free Technique , 2017, Nanoscale Research Letters.

[13]  K. Tamaki,et al.  Differential phase shift-quantum key distribution , 2008, IEEE Communications Magazine.

[14]  J. Coleman,et al.  Relating the optical absorption coefficient of nanosheet dispersions to the intrinsic monolayer absorption , 2015, 1511.04410.

[15]  J. F. Dynes,et al.  Room temperature single-photon detectors for high bit rate quantum key distribution , 2014 .

[16]  On-chip single photon emission from an integrated semiconductor quantum dot into a photonic crystal waveguide , 2011, 1201.3475.

[17]  B. Fimland,et al.  Position-controlled uniform GaAs nanowires on silicon using nanoimprint lithography. , 2014, Nano letters.

[18]  Mohammad Ali Mohammad,et al.  Fundamentals of Electron Beam Exposure and Development , 2012 .

[19]  Nikolai N. Ledentsov,et al.  RADIATIVE RECOMBINATION IN TYPE-II GASB/GAAS QUANTUM DOTS , 1995 .

[20]  Richard V. Penty,et al.  An introduction to InP-based generic integration technology , 2014 .

[21]  C. Q. Lee,et al.  Slow light in photonic crystals , 2005, Microelectron. J..

[22]  Q. Lu,et al.  Low Vπ high-speed GaAs travelling-wave electrooptic phase modulators using an n-i-p-n structure , 2009, European Quantum Electronics Conference.

[23]  Walther,et al.  Nonclassical radiation of a single stored ion. , 1987, Physical review letters.

[24]  Zhiyong Fan,et al.  Single InAs nanowire room-temperature near-infrared photodetectors. , 2014, ACS nano.

[25]  W. Lu,et al.  Distinct photocurrent response of individual GaAs nanowires induced by n-type doping. , 2012, ACS nano.

[26]  Gilles Brassard,et al.  Quantum Cryptography , 2005, Encyclopedia of Cryptography and Security.

[27]  Xiang-Bin Wang,et al.  Secure quantum key distribution in an easy way , 2010 .

[28]  T. Salame,et al.  Sensitive detection and identification of DNA and RNA using a patterned capillary tube. , 2011, Analytical chemistry.

[29]  Paul A. Dalgarno,et al.  Solid immersion lens applications for nanophotonic devices , 2008 .

[30]  L.-E. Wernersson,et al.  Vertical Enhancement-Mode InAs Nanowire Field-Effect Transistor With 50-nm Wrap Gate , 2008, IEEE Electron Device Letters.

[31]  Jared J. Hou,et al.  Tunable Electronic Transport Properties of Metal‐Cluster‐Decorated III–V Nanowire Transistors , 2013, Advanced materials.

[32]  Y. Makhlin,et al.  Quantum-state engineering with Josephson-junction devices , 2000, cond-mat/0011269.

[33]  R. Hadfield Single-photon detectors for optical quantum information applications , 2009 .

[34]  Y. Arakawa,et al.  Room-temperature triggered single photon emission from a III-nitride site-controlled nanowire quantum dot. , 2014, Nano letters.

[35]  C. M. Natarajan,et al.  Gallium arsenide (GaAs) quantum photonic waveguide circuits , 2014, 1403.2635.

[36]  Steven G. Johnson,et al.  Meep: A flexible free-software package for electromagnetic simulations by the FDTD method , 2010, Comput. Phys. Commun..

[37]  Gilles Brassard,et al.  Quantum cryptography: Public key distribution and coin tossing , 2014, Theor. Comput. Sci..

[38]  F. Marsili,et al.  Detecting single infrared photons with 93% system efficiency , 2012, 1209.5774.

[39]  G. Bastard,et al.  Photoluminescence of single InAs quantum dots obtained by self-organized growth on GaAs. , 1994, Physical review letters.

[40]  J. Song,et al.  Single-photon non-linear optics with a quantum dot in a waveguide , 2015, Nature communications.

[41]  Toshihiko Baba,et al.  Compact and fast photonic crystal silicon optical modulators. , 2012, Optics express.

[42]  Charles M. Lieber,et al.  High Performance Silicon Nanowire Field Effect Transistors , 2003 .

[43]  B. C. Richards,et al.  Modelling and fabrication of GaAs photonic-crystal cavities for cavity quantum electrodynamics , 2010, Nanotechnology.

[44]  W. Mccray,et al.  MBE deserves a place in the history books. , 2007, Nature nanotechnology.

[45]  F. Guinea,et al.  Strain engineering in semiconducting two-dimensional crystals , 2015, Journal of physics. Condensed matter : an Institute of Physics journal.

[46]  C. M. Natarajan,et al.  Chip-based quantum key distribution , 2015, Nature Communications.

[47]  Ryan Beams,et al.  Voltage-controlled quantum light from an atomically thin semiconductor. , 2015, Nature nanotechnology.

[48]  P. Lodahl,et al.  Interfacing single photons and single quantum dots with photonic nanostructures , 2013, 1312.1079.

[49]  R. Jaeger Introduction to microelectronic fabrication , 1987 .

[50]  S. Ruffenach,et al.  Indium nitride quantum dots grown by metalorganic vapor phase epitaxy , 2003 .

[51]  G. Sęk,et al.  Strong coupling in a single quantum dot semiconductor microcavity system , 2006, SPIE OPTO.

[52]  D. Law Semiconductors and semimetals, vol. 22, Lightwave Communication Technology, Part D - Photodetectors , 1986, IEEE Journal of Quantum Electronics.

[53]  D. Williams,et al.  Strongly coupled single quantum dot in a photonic crystal waveguide cavity , 2010, 1003.5185.

[54]  A. Faraon Locally controlled photonic crystal devices with coupled quantum dots: physics and applications , 2009 .

[55]  Bahram Nabet,et al.  Picosecond response times in GaAs/AlGaAs core/shell nanowire-based photodetectors , 2011 .

[56]  A. Lemaître,et al.  Optical nonlinearity for few-photon pulses on a quantum dot-pillar cavity device. , 2012, Physical review letters.

[57]  P. Krogstrup,et al.  Influence of the oxide layer for growth of self-assisted InAs nanowires on Si(111) , 2011, Nanoscale research letters.

[58]  E. Purcell Spontaneous Emission Probabilities at Radio Frequencies , 1995 .

[59]  Aaron M. Jones,et al.  Control of two-dimensional excitonic light emission via photonic crystal , 2013, 1311.6071.

[60]  M. Terrones,et al.  Defect engineering of two-dimensional transition metal dichalcogenides , 2016 .

[61]  O. Richard,et al.  Site Selective Integration of III–V Materials on Si for Nanoscale Logic and Photonic Devices , 2012 .

[62]  Enhancement and suppression of spontaneous emission by temperature tuning InAs quantum dots to photonic crystal cavities , 2006 .

[63]  M. Atatüre,et al.  Atomically thin quantum light-emitting diodes , 2016, Nature Communications.

[64]  S. Polyakov,et al.  : Single-photon sources and detectors , 2011 .

[65]  Zhiyong Fan,et al.  Diameter-dependent electron mobility of InAs nanowires. , 2009, Nano letters.

[66]  S. Gulde,et al.  Quantum nature of a strongly coupled single quantum dot–cavity system , 2007, Nature.

[67]  Yuan Wang,et al.  Monolayer excitonic laser , 2015, Nature Photonics.

[68]  A. Rogalski Infrared detectors: status and trends , 2003 .

[69]  J Fan,et al.  Invited review article: Single-photon sources and detectors. , 2011, The Review of scientific instruments.