Quantum Technologies 2018最新文献

{"title":"Front Matter: Volume 10674","authors":"","doi":"10.1117/12.2502121","DOIUrl":"https://doi.org/10.1117/12.2502121","url":null,"abstract":"","PeriodicalId":279431,"journal":{"name":"Quantum Technologies 2018","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124188839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On-demand single-photon source based on thermal rubidium (Conference Presentation)","authors":"Fabian Ripka, H. Kübler, R. Löw","doi":"10.1117/12.2309776","DOIUrl":"https://doi.org/10.1117/12.2309776","url":null,"abstract":"","PeriodicalId":279431,"journal":{"name":"Quantum Technologies 2018","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129817170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hybrid plasmonic waveguide coupled to a single organic molecule (Conference Presentation)","authors":"S. Grandi, M. Nielsen, J. Cambiasso, S. Boissier, K. D. Major, C. Reardon, T. Krauss, R. Oulton, E. Hinds, A. Clark","doi":"10.1117/12.2306890","DOIUrl":"https://doi.org/10.1117/12.2306890","url":null,"abstract":"Efficient photon sources will enable many quantum technologies. Single dibenzoterrylene (DBT) molecules are promising photon sources, but often emit in an unknown direction making photon collection challenging. Dielectric structures redirect emission into single optical modes [1], but are relatively large due to the diffraction limit of light. Plasmonic devices, such as antennae, can concentrate the electromagnetic field at the site of an emitter on a surface in volumes below the diffraction limit and redirect emission into well-controlled directions, but often suffer from losses. Recently, planar dielectric antennae have shown promise for redirecting emission [2], however often they do not provide single mode operation or compatibility with integrated photonics.\u0000\u0000Here we present a hybrid dielectric--metal approach in coupling a single molecule to an optical mode in an integrated planar device. We designed and fabricated a hybrid plasmonic waveguide (HPW) consisting of a dielectric slab with a nanoscale gap patterned in gold on the surface. Replacing the silicon layer used in our previous work [3] with titanium dioxide (TiO$_2$) allows operation at ~785 nm, the emission wavelength of DBT. Light propagating in the TiO$_2$ layer passes through the gap between the islands of gold. The width of the gap controls mode confinement: when the gap is <100 nm the propagating mode is mainly in the gap providing strong confinement; but when the gap is wider the mode decouples from the gold and propagates mainly in the TiO$_2$ with low loss. We deposited DBT-doped anthracene crystals on the surface using a supersaturated vapour growth technique [4]. Using confocal fluorescence microscopy we found a DBT molecule positioned near the gap. We then measured the saturation intensity of the molecule to be $I_{sat} = 325(27)$ kW/cm$^{2}$. Illuminating the molecule with a pulsed laser we measured the lifetime of the molecule to be 2.74(2) ns. Under CW excitation we measured the second-order correlation function $g^{(2)}(tau)$ of the light emitted directly into the microscope. This shows clear anti-bunching with $g^{(2)}(0)=0.25(6)$ proving this to be a single molecule. By detecting photons simultaneously from the microscope and from the grating coupler we measured $g^{(2)}(0)=0.24(6)$, demonstrating that this single molecule was emitting into the waveguide mode. By measuring the optical losses in our setup we calculated the coupling efficiency from the molecule to the HPW to be ~22%. This method provides a route to building waveguide sources of photons in planar integrated quantum photonic circuits for applications in quantum technology.\u0000\u0000[1] S. Faez et al., Phys. Rev. Lett. 113, 213601 (2014).\u0000[2] X. L. Chu et al., Optica 5, 203-208 (2014).\u0000[3] M. A. Nielsen et al., Nano. Lett. 16, 1410-1414 (2016).\u0000[4] C. Polisenni et al., Opt. Express 24, 5615-5627 (2016).","PeriodicalId":279431,"journal":{"name":"Quantum Technologies 2018","volume":"35 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133077384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ultrafast photonic quantum correlations mediated by individual phonons (Conference Presentation)","authors":"C. Galland, S. Tarrago, Mitchell D. Anderson","doi":"10.1117/12.2307193","DOIUrl":"https://doi.org/10.1117/12.2307193","url":null,"abstract":"","PeriodicalId":279431,"journal":{"name":"Quantum Technologies 2018","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131917468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pilot comparison on the measurement of detection efficiency of InGaAs/InP single-photon detectors (Conference Presentation)","authors":"Marco López","doi":"10.1117/12.2316332","DOIUrl":"https://doi.org/10.1117/12.2316332","url":null,"abstract":"InGaAs/InP single-photon detectors are today the most frequently used detectors for fibre-based Quantum Key Distribution (QKD) [1,2]. The performance of the QKD-systems greatly depends on the optical properties of its detector, such as quantum efficiency, dead time, dark counts, gating rate, etc., which need to be metrologically characterized to fully grantee the QKD network security. Therefore, several European National Metrological Institutes (NMIs) are putting today great efforts in developing novel measurement methods and calibration facilities, which allow to perform the traceable characterisation of single-photon detectors by using reference standards [3, 4]. From the metrological, and specifically radiometric, point of view, the detection efficiency of the single-photon detector is the main parameter that needs to be traceable to the primary standard for optical power (i.e. the cryogenic radiometer), which is maintained by most of the NMIs. \u0000\u0000Recently, four European NMIs have carried out a pilot comparison on the detection efficiency of a free-running InGaAs/InP single-photon detector, which main purpose has been to provide a snapshot of the measurement capabilities of the four European NMIs in the field of photon counting detection. The comparison was carried out in the framework of the EMPIR project 14IND05 “Optical metrology for quantum-enhanced secure telecommunication (MIQC2)” at the telecom wavelength of 1550 nm by using different reference standards with independently traceability chains. The results of this comparison, including the different experimental setups, the measurement methods, the traceability chain and the uncertainty evaluation of each participant, will be presented in this conference.\u0000\u0000References:\u0000[1] Akihisa Tomita, et al., “High speed quantum key distribution system”, Optical Fiber Technology, 16, Issue 1, 55-62 (2010).\u0000[2] Damien Stucki, et al., “Photon counting for quantum key distribution with peltier cooled InGaAs/InP APDs”, Journal of Modern Optics, 48, Issue 13, 1967-1981 (2001).\u0000[3] M. Lopez, et al, “Detection efficiency calibration of single-photon silicon avalanche photodiodes traceable using double attenuator technique, Journal of Modern Optics 62, S21 – S27, 2015.\u0000[4] G. Porrovecchio, et al., “Comparison at the sub-100 fW optical power level of calibrating a single-photon detector using a high-sensitive, low-noise silicon photodiode and the double attenuator technique”, Metrologia 53, 1115-1122 (2016).","PeriodicalId":279431,"journal":{"name":"Quantum Technologies 2018","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121307709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Forward-looking criteria for the certification of quantum key distribution (Conference Presentation)","authors":"Marco Lucamarini, J. Dynes, Zhiliang Yuan, M. Ward, A. Shields","doi":"10.1117/12.2317935","DOIUrl":"https://doi.org/10.1117/12.2317935","url":null,"abstract":"Technological advances in quantum computers and number theory have the potential to compromise the security of existing cryptographic protocols. Quantum key distribution (QKD) offers the possibility of information theoretic security and is theoretically unbreakable. Therefore it is the natural candidate to face the above digital threat. \u0000However, in implementing QKD, it is important to check that the components employed do not deviate from their expected behaviour, to avoid opening the door to new security loopholes [1]. For this reason, it is necessary to characterise the real behaviour of the components, build reliable models and include them in the security analysis.\u0000Here we introduce a set of techniques and measurements to ease this characterisation process. We discuss explicit examples applied to the source [2], the boundaries [3] and the detection unit [4] of a QKD apparatus. These methods pave the way to the future certification of QKD systems.\u0000[1] K. Tamaki, M. Curty, and M. Lucamarini, “Decoy-state quantum key distribution with a leaky source,” New J. Phys 18, 65008 (2016).\u0000[2] J. F. Dynes et al., “Testing the photon-number statistics of a quantum key distribution light source,” arXiv:1711.00440 (2017).\u0000[3] M. Lucamarini et al., “Practical Security Bounds Against the Trojan-Horse Attack in Quantum Key Distribution,” Phys. Rev. X 5, 031030 (2015).\u0000[4] A. Koehler-Sidki et al., “Setting best practice criteria for self-differencing avalanche photodiodes in quantum key distribution,” SPIE Proc. 10442, Quant. Inf. Sci. Tech. III, 104420L (2017).","PeriodicalId":279431,"journal":{"name":"Quantum Technologies 2018","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134412281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Single photon extraction from defects in hBN using a tapered fiber (Conference Presentation)","authors":"A. Schell, T. T. Tran, H. Takashima, I. Aharonovich, S. Takeuchi","doi":"10.1117/12.2307460","DOIUrl":"https://doi.org/10.1117/12.2307460","url":null,"abstract":"Efficient extraction of photons from quantum emitters is an important prerequisite for the use of such emitters in quantum optical applications as single photons sources or sensors. One way to achieve this is by coupling to a suited photonics structure, which guides away the emitter light. Here, we show the coupling of a single defect in hexagonal boron nitride (hBN) to a tapered optical fiber via a nanomanipulation technique [1]. Defects in hBN are capable of emitting single photons at room temperature while being photostable at the same time – two properties that make them ideal candidates for integration in single photon sources. The high control the manipulation technique provides avoids covering the whole nanofiber with emitters. We characterize the coupled system in terms of achievable count rates, saturation intensity, and spectral properties. Antibunching measurements are used to proof the single emitter nature of the defect. Our results pave the way for integration of single defects in hBN into photonic structure and their use as single photon sources in quantum optical applications such as quantum crypthography.\u0000[1] A W Schell et al., ACS Photonics, 4, 761–767 (2017)","PeriodicalId":279431,"journal":{"name":"Quantum Technologies 2018","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121136492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"LiY1-xHoxF4: a candidate material for the implementation of solid state qubits (Conference Presentation)","authors":"A. Beckert, J. Bailey, G. Matmon, S. Gerber, H. Sigg, G. Aeppli","doi":"10.1117/12.2307317","DOIUrl":"https://doi.org/10.1117/12.2307317","url":null,"abstract":"The model magnet LiY1-xHoxF4 has been shown to exhibit a variety of quantum many-body phenomena, such as quantum phase transitions, quantum annealing, long lived coherent oscillations and long-range entanglement, making LiY1-xHoxF4 a promising candidate for the implementation of solid state qubits. The magnetic moment of the Holmium atoms stems from the well screened f-shell electrons and the dynamics is largely dominated by dipolar interaction which can be tuned by doping concentration x. The energy levels of the rare-earth magnetic ion develop as follows: The degeneracy of the free-atom electron states arranged by the native strong spin-orbit interaction is lifted by the tetragonal crystal lattice symmetry (point group S4) and subsequently further split by the hyperfine interaction with the nuclear spin I=7/2. \u0000Earlier work optically probed the transition from the eightfold hyperfine-split ground state to the second excited state in a Fourier transform infrared (FTIR) spectrometer with a lab infrared source and 1.2 m optical path difference (OPD), hence with limited signal to noise ratio and resolution. We present data using high brilliance synchrotron radiation light in the far infrared regime from the Swiss Light Source (SLS) at Paul Scherrer Institut in Switzerland taken with a high resolution FTIR spectrometer featuring 11 m OPD allowing us to probe the ground state to second excited state transition hyperfine lines with unprecedented precision of 0.00077 cm-1 which corresponds to 23 MHz. This precision allows us to extract the full width half maximum (FWHM) of the hyperfine linewidths as function of temperature and three different concentrations (x=0.3%, 0.25%, 0.1%). We observe Arrhenius behavior of the linewidths as a function of temperature and decreasing linewidths for decreasing concentrations. For the lowest doping x = 0.1% and T=6 K we find an average FWHM of 0.006 cm-1, which corresponds to 180 MHz and a lower bound lifetime of 0.46 ns.\u0000As a next step, we push towards a more detailed examination of the absorption line shapes and intensities, and measurements of lower Holmium doping concentrations as well as other compounds with sharp absorption lines in the infrared regime.","PeriodicalId":279431,"journal":{"name":"Quantum Technologies 2018","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129286034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optical key distribution enhanced by optical injection locking (Conference Presentation)","authors":"G. L. Roberts, J. Dynes, S. Savory, Zhiliang Yuan, A. Shields, Marco Lucamarini","doi":"10.1117/12.2306125","DOIUrl":"https://doi.org/10.1117/12.2306125","url":null,"abstract":"Quantum key distribution (QKD) allows two users to communicate with theoretically provable\u0000secrecy [1]. This is vitally important to secure the confidential data of governments, businesses\u0000and individuals. As the technology is adopted by a wider audience, a quantum network will\u0000become necessary for multi-party communication, as in the classical communication networks in\u0000use today. Unfortunately, a number of phase-encoded QKD protocols based on weak coherent\u0000pulses have been developed. Whilst the first protocol, proposed by Bennett and Brassard\u0000in 1984 (BB84), is still commonly used, other protocols such as differential phase shift [2] or\u0000coherent one way QKD [3] are also adopted. Each protocol has its benefits; however all would\u0000require a different transmitter and receiver, increasing the complexity and cost of quantum\u0000networks.\u0000\u0000In this work we demonstrate a multi-protocol transmitter [4-6] that also has the benefits of\u0000small footprint, low power consumption and low complexity. We use this transmitter to give the\u0000first experimental demonstration of an improved version of the BB84 protocol, known as the\u0000differential quadrature phase shift protocol. We have achieved megabit per second secure key\u0000rates at short distances, and have shown secure key rates that are, on average, 2.71 times higher\u0000than the standard BB84 protocol. This enhanced performance over such a commonly adopted\u0000protocol, at no expense to experimental complexity, could lead to a widespread migration to\u0000the new protocol.\u0000\u0000The security of the BB84 protocol relies on each signal and reference pulse pair being globally\u0000phase randomised with respect to all other pulse pairs. In the DQPS protocol, blocks with a\u0000length L ≥ 2 are used and each block has a globally random phase with respect to all other blocks.\u0000Implementing this protocol would ordinarily require a high-speed random number generator and\u0000a phase modulator. As well as increasing device complexity, it would also require an unrealistic\u0000continuous source of electrical modulation signals for complete security. The transmitter we\u0000use injects light from a master laser diode into a 2 GHz gain-switched slave laser diode. The\u0000principal of optical injection locking means that the slave laser inherits the phase of the master\u0000laser. We apply modulations to the master laser current within a block to control the phase\u0000of the slave laser output pulses, and then drive the master laser below threshold for a short\u0000period of time when phase randomisation is required. This ensures the lasing comes from below\u0000threshold, thus the phase adopted by the slave laser pulse is completely random. We perform\u0000an autocorrelation measurement on the blocks to show their randomness.\u0000\u0000[1] N. Gisin et al. Rev. Mod. Phys. 74, 145 (2002).\u0000[2] K. Inoue et al. Phys. Rev. Lett. 89, 037902 (2002).\u0000[3] D. Stucki et al. Appl. Phys. Lett. 87 194108 (2005).\u0000[4] Z. Yuan et al. Phys. Rev. X. 6, 031044 (2016).\u0000[5] G. L. Roberts et al. Laser Phot. Rev. 11, 1700067 (2017).\u0000[6] ","PeriodicalId":279431,"journal":{"name":"Quantum Technologies 2018","volume":"552 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120955017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Alignment requirements of Fabry-Perot microresonators for ion trap quantum information processing (Conference Presentation)","authors":"D. Clarke, P. Horák","doi":"10.1117/12.2307152","DOIUrl":"https://doi.org/10.1117/12.2307152","url":null,"abstract":"In recent years there has been rapid progress into realising a working universal quantum computer, in particular with the development of chip-based radio frequency (RF) ion traps. The next significant leap will come with successfully integrating optical cavities into these ion traps to allow for interaction between remote ions via photons as required for more efficient and scalable quantum networking schemes. Fibre-tip cavities are especially interesting for such applications as they enable highly efficient coupling of photons from the cavity into optical fibres for onward transmission [1]. Ideally, one would like to operate such micro-resonators in the near-concentric regime that provides the smallest cavity mode waist and thus strongest coupling to a trapped ion. However, the cavity mode becomes unstable in this limit, and in practice ion-cavity systems are often operated far away from this regime.","PeriodicalId":279431,"journal":{"name":"Quantum Technologies 2018","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131996536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}