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Calendar of Physics Talks Vienna
| Hawking effect from gauge and gravitational anomalies |
| Speaker: | Rabin Banerjee |
| Abstract: | The recent approach of obtaining the Hawking flux from a black hole using gauge and gravitational anomalies is discussed. The role of boundary conditions in this derivation is explained. Finally, its connection with the vacuum structure is briefly stated.
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| Date: | Wed, 29.09.2010 |
| Time: | 14:15 |
| Duration: | 60 min |
| Location: | TU Wien, Inst. f. Theoret. Phys., SEM 136, Freihaus, Wiedner Hauptstr. 8-10/136, 10th floor, yellow |
| Contact: | Reinhold Bertlmann and Daniel Grumiller |
| Detection of correlations: from classical to quantum |
| Speaker: | Dagmar Bruss (University of Düsseldorf) |
| Abstract: | The mystery and power of quantum correlations has intrigued researchers for many decades. Here, a method for the detection of quantum correlations will be explained which is based on a link to the diffractive properties of a many-body system. An intuitive analogy of the detection of classical correlations to the corresponding entanglement witness will be presented. This talk is part of the CoQuS II kick-off workshop: http://www.coqus.at/events/coqus-ii-kick-off/
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| Date: | Thu, 30.09.2010 |
| Time: | 09:00 |
| Duration: | 45 min |
| Location: | Univ. Wien, Christian-Doppler-Hörsaal, Boltzmanngasse 5/3rd floor, 1090 Wien |
| Contact: | Christiane Losert-Valiente Kroon |
| Precision spectroscopy of cold molecular hydrogen ions: towards a determination of the electron‐to‐proton mass ratio |
| Speaker: | Stephan Schiller (Heinrich‐Heine‐University of Düsseldorf) |
| Abstract: | The hydrogen molecular ion is a three-body system and thus a fundamental system in quantum mechanics, and has been the subject of extensive theoretical work for over 80 years, with constantly increasing accuracy. The experimental efforts on high-resolution spectroscopy have been more limited, but have yielded several precise measurements of energies.
We have developed a molecular hydrogen ion experiment that applies modern techniques of cold gaseous matter manipulation with the aim of reaching significantly higher precision in rotational and vibrational spectroscopy. The overall goal is to use the hydrogen molecular ion for tests of quantum electrodynamics (QED) and the determination
of fundamental constants, in particular the electron-to-proton mass ratio. With this goal, our experiment explores a new avenue in the emerging field of fundamental physics with cold molecules.
Ensembles of cold, confined molecule ensembles are well suited for precision spectroscopy. However, standard laser cooling is not generally applicable to molecular species. In this case sympathetic cooling is a viable alternative. Here the atomic or molecular ensemble is brought in suitable contact with another ensemble of laser-cooled
atoms - as a result both ensembles are cooled. In our experiment, we cool hydrogen molecular ions using laser-cooled Beryllium atomic ions to temperatures as low as 10 mK [1]. Rovibrational spectroscopy of HD+ is performed using a destructive technique, 1+1’ resonance-enhanced photodissociation [2]. We have measured an overtone vibrational transition frequency using a frequency comb with 2-ppb relative accuracy [3]. This is a factor of 150 higher than previous results for HD+, and the measured transition frequency agrees well with recent high-accuracy ab initio calculations which include high order QED effects [4].
We are currently developing new approaches to enhance the sensitivity and resolution of our spectroscopic measurements.
For example, the population fraction of molecular ions in the lower spectroscopy state should be as large as possible, in order to obtain large signals. However, the population is spread over different rotational levels by the thermal equilibrium with the 300 K blackbody radiation. This has been modified by pumping more than 75% of the population from states with J>0 to the lowest rotational state, using two lasers (5.4 and 2.7 µm). Thereby rotational cooling of trapped molecular ions has effectively been realized for the first time [5].A next step will be to pump most of the population into a single hyperfine level of the ground state.
Preliminary results on fundamentel vibrational spectroscopy and pure rotational spectroscopy will be presented. On the theoretical side, the determination of the systematic line-shifting effects relevant for ultra-high resolution spectroscopy has started [6].
[1] P. Blythe, B. Roth, U. Fröhlich, H. Wenz, S. Schiller, Phys. Rev. Lett. 95, 183002 (2005)
[2] B. Roth, J. Koelemeij, H. Daerr, S. Schiller, Phys. Rev. A 74, 040501 (2006)
[3] J. Koelemeij, B. Roth, A. Wicht, I. Ernsting, S. Schiller, Phys. Rev. Lett. 98, 173002 (2007)
[4] V. Korobov, Phys. Rev. A 74, 052506 (2006)
[5] T. Schneider, B. Roth, H. Duncker, I. Ernsting, S. Schiller, Nature Physics 6, 275 (2010)
[6] D. Bakalov, V. Korobov, S. Schiller, arxiv.org:1007.3929v2
This talk is part of the CoQuS II kick-off workshop: http://www.coqus.at/events/coqus-ii-kick-off/ |
| Date: | Thu, 30.09.2010 |
| Time: | 11:00 |
| Duration: | 45 min |
| Location: | Univ. Wien, Christian-Doppler-Hörsaal, Boltzmanngasse 5/3rd floor, 1090 Wien |
| Contact: | Christiane Losert-Valiente Kroon |
| Ultra-cold neutrons, Berry’s geometric phase and superconducting quantum circuits |
| Speaker: | Stefan Filipp (ETH Zurich) |
| Abstract: | The adiabatic transport of a quantum system around a closed path in parameter space leads to a geometric contribution to the acquired phase, Berry’s phase. This phase depends only on the path, but not on dynamical quanti-
ties such as energy and evolution time. It is therefore considered to be robust against certain types of fluctuations. Using trapped ultra-cold neutrons exposed to time-varying, adiabatically fluctuating magnetic fields, it is experimentally demonstrated that the geometric component of dephasing vanishes for long evolution cycles. Furthermore, we have measured Berry’s geometric phase with superconducting quantum circuits. These multi-level artificial atoms provide a versatile platform for investigations of geometric phases of single and multi-particle systems.
This talk is part of the CoQuS II kick-off workshop: http://www.coqus.at/events/coqus-ii-kick-off/ |
| Date: | Thu, 30.09.2010 |
| Time: | 14:30 |
| Duration: | 45 min |
| Location: | Univ. Wien, Christian-Doppler-Hörsaal, Boltzmanngasse 5/3rd floor, 1090 Wien |
| Contact: | Christiane Losert-Valiente Kroon |
| Cavity optomechanics: back‐action cooling of mechanical oscillators |
| Speaker: | Tobias Kippenberg (Ecole Polytechnique Federale de Lausanne (EPFL)) |
| Abstract: | The mutual coupling of optical and mechanical degrees of freedom via radiation pressure has been a subject of interest in the context of quantum limited displacements measurements for Gravity Wave Detection for many decades. Recent advances in nano- and micro-mechanical oscillators have allowed the observation for the first time of radiation pressure phenomena in an experimental setting and constitute the emerging research field of Cavity Optomechanics(1).
Using on-chip micro-cavities that combine both optical and mechanical degrees of freedom in one and the same device(2), radiation pressure back-action of photons is shown to lead to effective cooling(3-6) of the mechanical oscillator mode. This back-action cooling exhibits many close analogies to the physics of atomic laser cooling. The case of resolved sideband cooling in the quantum regime will be mentioned, which has enabled preparation of a 75 MHz mechanical oscillator with only 20 quanta(5). In addition, measurements of both micro- and nanomechanical motion at the standard quantum limit of motion measurement will be presented(7).
Time permitting, other analogies such as optomechanical electromagnetically induced transparency will be described and other outstanding challenges such as that to reach the quantum ground state of a mechanical oscillator described.
References:
1. T. J. Kippenberg, K. J. Vahala, Science 321, 1172 (2008, 2008).
2. T. J. Kippenberg, H. Rokhsari, T. Carmon, A. Scherer, K. J. Vahala, Physical Review Letters 95, 033901 (2005).
3. V. B. Braginsky, S. P. Vyatchanin, Physics Letters A 293, 228 (Feb 4, 2002).
4. V. B. Braginsky, Measurement of Weak Forces in Physics Experiments (University of Chicago Press, Chicago, 1977), pp.
5. A. Schliesser, O. Arcizet, R. Riviere, G. Anetsberger, T. J. Kippenberg, Nature Physics 5, 509 (2009).
6. A. Schliesser, P. Del'Haye, N. Nooshi, K. J. Vahala, T. J. Kippenberg, Physical Review Letters 97, 243905 (Dec 15, 2006).
7. G. Anetsberger, O. Arcizet, Q. P. Unterreithmeier, E. M. Weig, J. P. Kotthaus, T. J. Kippenberg, Nature Physics (Nature Physics) (2009).
This talk is part of the CoQuS II kick-off workshop: http://www.coqus.at/events/coqus-ii-kick-off/ |
| Date: | Thu, 30.09.2010 |
| Time: | 16:30 |
| Duration: | 45 min |
| Location: | Univ. Wien, Christian-Doppler-Hörsaal, Boltzmanngasse 5/3rd floor, 1090 Wien |
| Contact: | Christiane Losert-Valiente Kroon |
| Ultracold fermionic mixtures in optical lattices |
| Speaker: | Lucia Hackermüller (The University of Nottingham) |
| Abstract: | Ultracold fermions in optical lattices are a promising tool to simulate solid state physics, since they represent an ideal and highly tunable implementation of the Hubbard Hamiltonian. A proof of principle is to demonstrate a Mott insulating state, where repulsive interactions between the atoms lead to an insulating behavior in a half-filled conduction band.
In our experiments we study repulsively and attractively interacting 40K atoms within the combination of a red-detuned dipole trap with a blue detuned lattice. This setup allows us to gradually transform the system from metallic to Mott-insulating and band insulating states. We measure the phase of the system by analyzing the system size and the number of doubly occupied sites and compare our findings to DMFT theory.
In addition we investigate the dynamical behavior of interacting fermionic mixtures. We prepare a band insulating system and suddenly release it into a homogenous lattice. This allows us to study transport properties of the Hubbard model.
This talk is part of the CoQuS II kick-off workshop: http://www.coqus.at/events/coqus-ii-kick-off/ |
| Date: | Thu, 30.09.2010 |
| Time: | 17:55 |
| Duration: | 45 min |
| Location: | Univ. Wien, Christian-Doppler-Hörsaal, Boltzmanngasse 5/3rd floor, 1090 Wien |
| Contact: | Christiane Losert-Valiente Kroon |
| Probing the electron EDM with cold molecules |
| Speaker: | Ed Hinds (Imperial College London) |
| Abstract: | The search for an electron EDM is a search for new particle physics. We are measuring the electron EDM using a beam of cold YbF. The present version of our experiment has the statistical sensitivity to make a measurement at the level of a few times 10^{−28} e.cm. and this is in progress. Several upgrades now in preparation, will give a further tenfold improvement in sensitivity. I will discuss the present status of this programme and future prospects.
There is now a strong prospect of greatly improving sources of cold molecules towards much higher intensity and also towards much lower temperature. I will describe some of these methods and the new physics that is starting to become accessible as a result.
This talk is part of the CoQuS II kick-off workshop: http://www.coqus.at/events/coqus-ii-kick-off/ |
| Date: | Fri, 01.10.2010 |
| Time: | 09:00 |
| Duration: | 45 min |
| Location: | Univ. Wien, Christian-Doppler-Hörsaal, Boltzmanngasse 5/3rd floor, 1090 Wien |
| Contact: | Christiane Losert-Valiente Kroon |
| Tests of quantum mechanics and CPT symmetry in the neutral kaon system |
| Speaker: | Antonio Di Domenico (Sapienza University of Rome) |
| Abstract: | The neutral kaon system offers a unique possibility to perform fundamental tests of CPT invariance, as well as of the basic principles of quantum mechanics. The most recent limits on several kinds of possible CPT violation and decoherence mechanisms are reviewed, with special emphasis on results obtained by the KLOE experiment at the DAFNE e+e- collider. No deviation from the expectations of quantum mechanics and CPT symmetry is observed, while the precision of the measurements is remarkable, and in some cases reaches the interesting Planck scale region.
The extension of this physics program, including e.g. a possible realization of a kaonic quantum eraser, with the KLOE-2 experiment at the upgraded DAFNE machine is also discussed.
This talk is part of the CoQuS II kick-off workshop: http://www.coqus.at/events/coqus-ii-kick-off/ |
| Date: | Fri, 01.10.2010 |
| Time: | 11:00 |
| Duration: | 45 min |
| Location: | Univ. Wien, Christian-Doppler-Hörsaal, Boltzmanngasse 5/3rd floor, 1090 Wien |
| Contact: | Christiane Losert-Valiente Kroon |
| Is cryptographic security premised upon Quantum Field Theory more powerful than that premised upon Non-Relativistic Quantum Mechanics? |
| Speaker: | Terry Rudolph (Imperial College London) |
| Abstract: | Yes.
This talk is part to the CoQuS II kick-off workshop: http://www.coqus.at/events/coqus-ii-kick-off/ |
| Date: | Fri, 01.10.2010 |
| Time: | 11:45 |
| Duration: | 45 min |
| Location: | Univ. Wien, Christian-Doppler-Hörsaal, Boltzmanngasse 5/3rd floor, 1090 Wien |
| Contact: | Christiane Losert-Valiente Kroon |
| Pedagogical introduction to anomalies and black holes |
| Speaker: | Rabin Banerjee (S.N. Bose National Center for Basic Sciences, Calcutta) |
| Abstract: | The concept of an anomaly is introduced in general terms. Its role in physics is highlighted. Correspondingly, black holes are introduced intuitively without using general relativity. Then a connection between anomalies and black holes is established to discuss the Hawking effect.
This talk is part of the CoQuS II kick-off workshop: http://www.coqus.at/events/coqus-ii-kick-off/ |
| Date: | Fri, 01.10.2010 |
| Time: | 14:30 |
| Duration: | 45 min |
| Location: | Univ. Wien, Christian-Doppler-Hörsaal, Boltzmanngasse 5/3rd floor, 1090 Wien |
| Contact: | Christiane Losert-Valiente Kroon |
| Bertlmann’s Socks in Particle Physics and Relativistic Entanglement |
| Speaker: | Beatrix Hiesmayr (Slovak Academy of Sciences) |
| Abstract: | Entanglement and its manifestations can also be investigated for systems not consisting of ordinary matter or light, a research field Reinhold Bertlmann pioneered in and which is now part of the research program of the KLOE experiment at the accelerator facility DAPHNE (Italy). I will present how Bertlmann’s Socks behave in a Einstein-Podolsky-Rosen scenario for meson-antimeson systems which are entangled in their quantum number flavour. These systems are oscillating and decaying in time and differently to other systems they violate the CP symmetry (C...charge conjugation, P...parity), which relates the behaviour of matter and antimatter. In detail, I present a generalized Bell inequality and show some interesting choices of observables, e.g. a Bell inequality that is violated by the CP violating parameter. In the second part of the talk I discuss systems of massive spin ½ particles and describe how the entanglement of spin and momentum degrees of freedom change, when considered by different inertial observers. Last but not least I demonstrate how the maximally possible degree of violation of a Bell inequality, using the Pauli-Lubanski spin observable, can be recovered by any inertial observer.
This talk is part of the CoQuS II kick-off workshop: http://www.coqus.at/events/coqus-ii-kick-off/ |
| Date: | Fri, 01.10.2010 |
| Time: | 15:15 |
| Duration: | 45 min |
| Location: | Univ. Wien, Christian-Doppler-Hörsaal, Boltzmanngasse 5/3rd floor, 1090 Wien |
| Contact: | Christiane Losert-Valiente Kroon |
| Quantum entanglement and the foundations of quantum mechanics |
| Speaker: | Anton Zeilinger (Universität Wien & IQOQI Wien) |
| Abstract: | Experiments in quantum information science, having emerged from experiments testing the foundations of quantum physics, are giving rise to a renewed debate about just these foundations. Most notably entanglement, dismissed as “spooky” by Einstein while called “the characteristic trait of quantum mechanics” by Schrödinger and as signified by John Bell and explained so nicely in hsi artcile on Bertlmann's socks emerged as a central fundamental concept.. It is also an important, in cases even crucial notion, for procedures like quantum cryptography, quantum computation, and quantum teleportation. Today entangled states can cover large distances, for example between two Canary Islands, and employ a significant number of particles and many different kinds of degrees of freedom, internal and external. The resulting development of experimental tools opened up possibilities for new experiments shedding more light on fundamental questions. The emerging picture is that the notions of reality or objectivity have to be scrutnized more deeply and information itself plays a fundamental role in the understanding the foundations of quantum mechanics.
This talk is part of the CoQuS II kick-off workshop: http://www.coqus.at/events/coqus-ii-kick-off/ |
| Date: | Fri, 01.10.2010 |
| Time: | 16:30 |
| Duration: | 45 min |
| Location: | Univ. Wien, Christian-Doppler-Hörsaal, Boltzmanngasse 5/3rd floor, 1090 Wien |
| Contact: | Christiane Losert-Valiente Kroon |
| Magic Moments of a Physicist |
| Speaker: | Reinhold Bertlmann (Universität Wien) |
| Abstract: | A recollection is given of my activities as a physicist. Beginning with my thesis and postdoc work on electromagnetic and weak interactions I report on my stays at JINR Dubna, CERN and University of Marseilles. In particular, I will talk about my collaboration with John Bell. Summarizing my work on QCD and anomalies in quantum field theory I describe my turn to quantum mechanics in the recent years, where I could show the significance of entanglement and decoherence in the “strange” and “beauty” quantum systems of particle physics.
This talk is part of the CoQuS II kick-off workshop: http://www.coqus.at/events/coqus-ii-kick-off/ |
| Date: | Fri, 01.10.2010 |
| Time: | 17:15 |
| Duration: | 45 min |
| Location: | Univ. Wien, Christian-Doppler-Hörsaal, Boltzmanngasse 5/3rd floor, 1090 Wien |
| Contact: | Christiane Losert-Valiente Kroon |
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