Day 2 :
- Track 3: Quantum States
Track 4: Quantum Mechanics Interpretation
Track 5: Strings in Quantum Physics
RIKEN Center for Emergent Matter Science, Japan
Ulm University, Germany
Tamagawa University, Japan
Time : 09:30-09:55
Osamu Hirotahas received his PhD in 1979 from Tokyo Institute of Technology (Japan). He is Director of the Quantum ICT Research Institute of Tamagawa University and is one of the pioneers of quantum information science. He has established International Conference on Quantum Communication, Measurement and Computing (QCMC) in 1990. He has published more than 100 papers, in particular on quantum state discrimination theory and entangled coherent state.
Non-orthogonal quantum states in infinite dimensional space are playing a special role in foundation of quantum mechanics. The Gaussian state is a typical example of such a state that was considered at beginning of history of quantum theory. The explicit importance of Gaussian quantum states such as coherent state was certified by R Glauber, ECG Sudarshan et al in quantum optics for understanding a nature of laser. More progress has been given by H P Yuen who discovered a special property of generalized coherent state known as squeezed state and a method to verify them experimentally. Then current interest goes to entanglement of non-orthogonal quantum state such as two-mode squeezed state and quasi-Bell entangled coherent state. On the other hand, a problem of discrimination of non-orthogonal quantum states through quantum measurement that was pioneered by C W Helstrom is also a foundation of quantum physics. Its basic criteria are Bayes, Neyman-Peason, and Minimax which play different roles. In this talk, I present a historical survey of importance of non-orthogonal quantum state, and progress of quantum state discrimination. Also I introduce potential applications of theoretical achievements on non-orthogonal quantum state such as Quantum Methodology and Quantum Enigma Cipher based on recent experimental progress.
Max-Planck-Institute for the Science of Light, University of Erlangen-Nürnberg, Germanyy
Time : 09:55-10:20
N Y Joly is an Associate Professor at the University of Nüremberg-Erlangen, where he works on photonic crystal fibers in close collaboration with the division of Prof. Philip Russell at the Max-Planck Institute for the Science of Light. His domain of research includes dynamics of fs-pulsed ring cavity as well as nonlinear optics in PCF. In particular he is very interesting in the nonlinear generation of new frequencies like supercontinuum generation.
Photonic crystal fibers (PCF) offer an important platform for 3-based nonlinear optics owing to the possibility to fully tailor their dispersion properties or modify the number of guided modes. We present here two ways to use these fibers in order to generate non-classical states of light, which are important tools for quantum technologies. First, we show the generation of bright correlated twin beams, based on modulation instability in a kagomé-lattice hollow-core PCF filled with argon at high pressure. In this experiment, we used 300 fs pump pulses from a Ti:Sa regenerative system (=800 nm) to generate modulation-instability sidebands. We then observed twin-beam squeezing up to 35% below the shot-noise level. This very bright source is spatially single mode and can exhibit only a few temporal modes (<5). Second, we introduce a new design of micro structured fiber for the generation ofthe photon-triplet state through a direct decay of pump photons. Similarly to the third harmonic generation, the phase matching is usually not satisfied for the fundamental spatial modes due to chromatic dispersion. The spatial overlap is therefore small and the efficiency of the process is consequently poor. Here we use a hybrid solid-core PCF, in which total internal reflection occurs at down-converted wavelengths while an all-solid band gap governs the guidance mechanism at the pump wavelength. The overall dispersion is strongly influenced by these two mechanisms. Preliminary experiments on third harmonic generation confirm that the phase-matching between fundamental modes is indeed possible with this structure.
TU-Wien Atominstitut der Österreichischen Universitäten, Austria
Title: Fundamental phenomena of quantum mechanics studied in matter-wave optics: Quantum Cheshire-cat and uncertainty relations
Time : 10:20-10:45
Yuji Hasegawa has completed his PhD from the University of Tokyo. During and after his study, he spent several years at the Atominstitut der Österreichischen Universitäten, Vienna and became University Assistant at the University of Tokyo. He was a Lise-Meitner Fellow by Austrian Science Fund (FWF) and a PRESTO Fellow by Japan Science and Technology Agency (JST). Now he is Associate Professor at the Vienna University of Technology (TU-Wien). He has published more than 100 papers in reputed journals.
The validity of quantum-mechanical predictions has been confirmed with a high degree of accuracy in a wide range of experiments. Although the statistics of the outcomes of a measuring apparatus have been studied intensively, little has been explored and is known regarding the accessibility of quantum dynamics and the evolutions of a quantum system during measurements. For this sort of fundamental studies of quantum mechanics, interferometric and polarimetric approaches, in particular by the use of neutron’s matter-waves, provide almost ideal experimental circumstances. The former device explicitly exhibits quantum interference between spatially separated beams in a macroscopic scale. In contrast, interference effects between two spin eingenstates are exposed in the latter apparatus. Exploiting both strategies, alternative theories of quantum mechanics, Kochen-Specker theorem and so on are studied. Recently, as a study of quantum dynamics, neutron interferometer experiments are carried out: a new counter-intuitive phenomenon, called quantum Cheshire-cat, is observed. Moreover, extending the first experimental test of the new error-disturbance uncertainty relation by using a modified neutron polarimeter setup, we performed experiments investigating the validity of an extended uncertainty relation for mixed ensemble as well as a new noise-disturbance uncertainty relation in an entropic form. In my talk, I am going to give an overview of matter-wave optical approach to investigations of fundamental aspect of quantum mechanics.
QuBS, JAEA & CEMS, RIKEN, Japan
Time : 11:05-11:30
Kazuhisa Kakurai has completed his PhD from TU Berlin working at the Hahn-Meitner Institut, Berlin. He joined the Institute for Solid State Physics of the University of Tokyo as an Assistant Professor and became a Professor in 1997. He was the Director General of the QuBS Directorate at the JAEA until 2014 and now serves as a General Adviser in the QuBS Center, JAEA in Tokai, Japan. Currently he is also Visiting Scientist at CEMS, RIKEN in Wako, Japan.
Magnetic neutron scattering experiments have been playing important role to probe the quantum ground state magnetism in condensed matter physics. In this review talk I would like highlight series of inelastic neutron magnetic scattering investigations on low-dimensional magnetic systems clarifying the roles of classical fluctuations and quantum fluctuations. They include the investigations on non-linear soliton excitations in one-dimensional spin chain systems, on quantum renormalization of spin-wave excitations, on spin on excitations in S=1/2 anti-ferromagnetic Heisenberg chain, on Haldane gap for antiferromagnetic integer spin Heisenberg chain and on spin dimer systems. In these examples the microscopic knowledge of spin fluctuations provided by neutron scattering, including polarized neutron scattering, was essential to recognize the key features of macroscopic quantum ground state magnetism. The state-of-the-art scattering instruments at modern neutron facilities worldwide designed to perform these key experiments will be also briefly introduced.
Colin Wilmott received is PhD in mathematics from Royal Holloway, University of London. Following this, he held a two year Assistant Lectureship at University College Dublin, before going on to undertake a DFG-supported Postdoctoral Fellowship at Heinrich-Heine Universitaet Duesseldorf as well as a Marie Curie Fellowship at Masaryk University. He is also the recipient of one further Marie Curie Fellowship, but declined this offer to take up his present position as Senior Lecturer in mathematics at Nottingham Trent University.
We present a novel approach that generalizes the well-known quantum SWAP gate to higher dimensions and construct a regular quantum gate composed entirely in terms of the generalized CNOT gate that cyclically permutes the states of d qudits, for d prime. We also investigate the case for d other than prime. A key feature of the construction design relates to the periodicity evaluation for a family of linear recurrences which we achieve by exploiting generating functions and their factorization over the complex reals.
Max-Planck Institute for the Science of Light, Germany
Time : 11:55-12:20
Maria Chekhova has completed her PhD in 1989 from the Lomonosov Moscow State University (Russia) and her habilitation degree from the same University in 2004. She is the Leader of a research group in Max-Planck Institute for the Science of Light in Erlangen, Germany, working in the field of generation and application of non-classical light (single photons, photon pairs, twin beams). She teaches a course of quantum optics at the University Erlangen-Nuremberg and a course on non-classical light at Moscow State University. She has published more than 100 papers in peer-reviewed journals.
Bright squeezed vacuum is a macroscopic state of light featuring non-classical properties, from photon-number entanglement and quadrature squeezing to the violation of certain types of Bell’s inequalities. By producing this state of light through high-gain parametric down-conversion in two coherently pumped crystals, one obtains a nonlinear interferometer, which offers various interesting possibilities. Among others, this is shaping the bright squeezed vacuum in space/angle and time/frequency, with the ultimate goal being to achieve a single-mode state. Moreover, this single mode can be of any desired shape, both in space and time. In our recent experiments, we have achieved generation of bright squeezed vacuum with a single spatial mode by spatially separating the two crystals forming the nonlinear interferometer. This mode had Gaussian shape but under certain conditions, spatial modes with non-zero optical angular momentum could be also obtained. By completing the nonlinear interferometer with a dispersive medium placed inside it, we achieved the generation of bright squeezed vacuum with only 1.5 frequency modes. The obtained single-mode bright squeezed vacuum can be used for various applications such as conditional preparation of non-Gaussian states, sensitive quantum phase measurements, and enhanced nonlinear optical effects.
Freelance Scientist, UK
Title: A consistent account of brain function reinterprets the evidence on which quantum mechanics is based
Time : 12:20-12:45
Michael T Deans graduated from Churchill College Cambridge in Natural Sciences, from UCL with an MSc in Biochemistry, programmed an IBM 360 and Commodore PET from the London Borough of Hounslow and his PhD thesis was compiled at King's College Hospital School of Medicine and Dentistry.
The ‘minion’, a coiled molecular abacus comprising 1,701 DNA base pairs bound to 189 protein units, evolved to pack chromosomes for efficient replication, explains human intelligence better than ‘neural networks’. Its 18*63 array of orderly hydrogen bonds connecting amino acids to phosphates stores an 18-character ‘word’. Memory recall involves resonance between similar minions, nerve fibres serving as wave guides and synapses as gates. Dynamically, they constitute 18-handed clocks, their time unit, τ ≈ 1.4*10-15 secs, and longest conceivable time, 6318 τ ≈ the ‘age of the universe’ limit our perception. In physics, τ replaces Planck’s constant. A hyperbolic function, the ‘Tyger equation’ corrects a wrap-around counting ‘error’, β=63-9 creating relativity twixt perception and conception. Light appears to follow a boomerang-like trajectory, our perception of space is warped, reinterpreting gravity and rendering plane surfaces as spheres. Mathematical logic using 0, ∞ and infinitesimal calculus creates an illusory world model. Familiar situations confirm Einstein’s spooky action at a distance. Substituting a set of nine polyhedrons reminiscent of Plato’s perfect solids for electron orbitals offers new insights to Mendeleev’s periodic table of elements. Protons accelerated by oscillating H-bonds through minion tunnels have sufficient energy to fuse with obstructing nuclei. Perhaps the γ-rays (evidenced by correlations with the periods and frequencies of pulsars) could be harnessed to supply power. Modelling computers and data-bases on minions could create user-friendly interfaces compensating for personality differences and facilitating understanding and agreement.
Institut für Quantenoptik und Quanten information, Austria
Time : 12:45-13:10
Gabriela Barreto Lemos has completed her PhD from the Federal University of Rio de Janeiro (Brazil), working with theoretical quantum chaos and open quantum system dynamics. She went on to do experiments in quantum information, quantum chaos, optics quantum imaging. She is currently finishing her Post-doc at IQOQI-Vienna under the supervision of Prof. Anton Zeilinger.
Quantum effects have led to novel concepts that overcome classical possibilities. Of these interaction-free measurement and high-contrast ghost imaging have received notable attention. Here, we exploit a non-linear single-photon interference experiment introduced in the early 1990s to study fundamental aspects of quantum optics and also show its applications to quantum imaging and spectroscopy. Our experiments use spontaneous parametric down conversion, but require no coincidence detection. We discuss the role of quantum indistinguishability in quantum imaging and measures of continuous-variable correlations in SPDC. We also establish a connection between path indistinguishability and the degree of polarization of the light in our experiment, thus presenting both theoretically and experimentally a case where the partial polarization of a light beam has a solely quantum origin.
- Track 9: Nuclear Science
Track 10: Interaction and Maintenance
Bilkent University, Turkey
Nottingham Trent University, UK
Alexander Kubanek has completed his PhD from Max-Planck Institute of Quantum Optics and Technical University Munich (Germany). He spent 4 years as Post-Doctoral Fellow / Research Associate at Physics Department of Harvard University. Since 2014, he is Carl-Zeiss Professor at Quantum Optics Institute of Ulm University. He was Fellow of Bavarian Network of Excellence and International PhD-Program Quantum Computing, Communication and Control and Feodor Lynen Fellow of Alexander von Humboldt Foundation. He has publication papers in Nature, Nature Physics and Physical Review Letters.
Implementing efficient, highly controllable light-matter interfaces is essential to realizing the goal of solid-state quantum networks. The nitrogen-vacancy (NV) center in diamond is a promising candidate for such interfaces due to favorable properties, such as long coherence times or single shot readout capabilities. Creating optical links between remote NV centers was an outstanding challenge until the recent demonstration of photon-mediated spin-spin entanglement between NV centers separated by three meters. I will present robust control of two remote NV centers demonstrating Hong-Ou-Mandel interference to verify the indistinguishability of photons produced by remote NV centers. The NV center’s application as quantum register depends on the ability to resonantly drive closed cycling transitions and closed lambda transitions with high fidelity. The fidelity can be degraded by phonon-induced mixing within the excited state manifold, which can provide unwanted non-radiative decay channels. I will present detailed investigation of phonon-induced mixing mechanism. Besides the importance to control phonon processes for applications of the NV center in Quantum Information, the NV center’s broad range of applications as sensors relies on the ability to initialize and readout the electronic state with off-resonant laser light. Both, initialization and read out rely on an inter-system crossing (ISC) process into a meta-stable state, a phonon-assisted shelving process that has not been fully explained. We have measured the ISC rate for different excited states and developed a model that unifies the phonon-induced mixing and ISC mechanisms. Finally, I will give an outlook into recent developments with other color centers in diamond.
Bilkent University, Ankara, Turkey
Time : 14:20-14:45
Prof. Dr. Ekmel Ozbay received M.S. and Ph. D. degrees from Stanford University in electrical engineering, in 1989 and 1992. He worked as a postdoctoral research associate in Stanford University and he worked as a scientist in Iowa State University. He joined Bilkent University (Ankara, Turkey) in 1995, where he is currently a full professor in Department of Electrical-Electronics Engineering. He is the director of Bilkent University Nanotechnology Research Center. His research in Bilkent involves nanophotonics, nanometamaterials, nanoelectronics, nanoplasmonics, nanodevices, photonic crystals, GaN/AlGaN MOCVD growth, fabrication and characterization of GaN based devices, and high speed optoelectronics.
In this talk, we will present how metamaterials can be used for nanobiosensors and nanophotode-tector applications. We will present a label-free, optical nano-biosensor based on the Localized Surface Plasmon Resonance (LSPR) effect that is observed at the metal-dielectric interface of sil-ver nano-cylinder arrays located periodically on a sapphire substrate by E-Beam Lithography (EBL), which provides high resolution and flexibility in patterning. We will also report on UV plasmonic antenna integrated metal semiconductor metal (MSM) photodetectors based on GaN. We also report the design, fabrication, and measurement of a device comprising a split-ring resonator array on epitaxial graphene.
Chitkara University, India
Time : 14:45-15:10
Ajay Sharma completed his PhD in Atomic and Radiation Physics from Nuclear Science Laboratories, Punjabi University, India. He has 15 years of teaching and research experience. His research interest includes; atomic inner shell studies and its quantum mechanical comparison for different parameters. He has a number of publications in journals of repute and a book on alignment studies. He is a life member of Indian society for atomic and molecular Physics (ISAMP) and Indian society for radiation Physics (ISRP). He is also serving as reviewer and Editorial Board Member of repute.
Alignment is accounted in terms of alignment parameter A20, the fractional difference of the photo-ionization cross-sections of magnetic sub-states. The alignment of vacancies results in anisotropic distribution of x-rays originating from the filling of the vacancies as alignment is exhibited by directional correlation and polarization of characteristic X-rays and Auger electrons emitted on decay of the vacancies. Direct measurements of dependence of photo-effect on magnetic sub-states are not possible, but can be derived from the observed radioactive transitions or non-radioactive emissions. In the current work alignment studies are made for rare earth and high Z-elements using theoretical, empirical and experimental approaches. The theoretical value of alignment parameter A20 has been calculated by using the non-relativistic dipole approximation in a point Coulomb potential and analytical perturbation theory in a screened Coulomb potential. For empirical evaluations IGELCS interpolated experimental LXRF cross-section values are used along with radiative decay rates. The experimental measurements have been performed in XRF laboratories of Raja Ramanna Centre for advanced technology (RRCAT-India) using a three dimensional double reflection set-up. The comparison of alignment studies has been found almost similar via above methods and the alignment values at the L3 threshold energy >0.1were certainly higher (5-8%) than the earlier quoted experimental results of various groups.
Poster presentations 15:30-16:00