|
Calendar of Physics Talks Vienna
| Manipulation and detection of spin entanglement with quantum dots |
| Speaker: | Seigo TARUCHA (Applied Physics Department, Tokyo University) |
| Abstract: | Manipulation of quantum entanglement is the core of quantum computation and has recently been implemented in solid state systems for spins and superconducting Josephson junctions. The local entanglement is typically the case for spin singlet states, and its manipulation enables to prepare universal sets of logical gates in quantum computing. We have recently used a two qubit gate of combined spin rotation and spin exchange coupling to control spin entanglement in double quantum dots [1]. On the other hand, the concept of non-local entanglement is well established for correlated photon pairs but not yet for solid state systems because of the strong interaction with environment. We have recently proposed new schemes of manipulating and detecting non-local entanglement using a technique of surface acoustic wave (SAW) and quantum dot Josephson junctions. In this talk I will review the schemes of manipulating local and non-local spin entanglement with quantum dots.
We previously demonstrated that an electron can be trapped and moved by a SAW burst from one dot to another [2]. This SAW technique can also be used to transfer two electrons or singlet pair through a quantum wire and separate them into two branches of an AB ring connected to the wire. The entanglement may be maintained for the split electrons in the AB ring if the transport through the system is phase coherent [3]. In addition, we have recently prepared a Josephson junction including single InAs quantum dots to observe the Josephson current significantly depending on the charge state because the pair tunneling or local Josephson current is strongly influenced by Coulomb blockade effect [4]. Now we use a similar Josephson junction but including two parallel coupled InAs quantum dots to study the non-local Josephson current, which may be larger than the local Josephson current. We observe the supercurrent depending on the double dot charge state and discuss the contribution from the split Cooper pair tunneling through two separate dots as a non-local process.
[1] R. Brunner, Y.-S. Shin, T. Obata, Y. Tokura, M. Pioro-Ladrière,T. Kubo,T. Taniyama, and S. Tarucha, Phys. Rev. Lett. 107, 146801 (2011).
[2] S. Hermelin, S. Takada, M.Yamamoto, S. Tarucha, A.D. Wieck, L. Saminadayar, C. Bäuerle, and T. Meunier, Nature 477, 435 (2011).
[3] M. Yamamoto, S. Takada, C. Bäuerle, K. Watanabe, A.D.Wieck, and S. Tarucha, Nature Nano. 7, 247 (2012).
[4] Y. Kanai, R. S. Deacon, A. Oiwa, K. Yoshida, K. Shibata, K. Hirakawa, and S. Tarucha, Appl. Phys. Lett. 100, 202109 (2012).
|
| Date: | Mon, 10.12.2012 |
| Time: | 17:30 |
| Location: | Uni Wien, Lise-Meitner-Hörsaal, Strudlhofg. 4, 1090 Wien |
| Contact: | Markus Arndt |
| Some notes on Solitons in classical and constructive field theory |
| Speaker: | Dima Pimenov (Mathematische Physik) |
| Abstract: | In this talk I will introduce the notion of Solitons in classical field theory. These can be regarded as special physically relevant solutions of Lagrangian equations of motion, which have interesting features even on the classical level. Based on few examples I will then sketch the rigorous construction of the so called “soliton-sectors” in low dimensional models in algebraic quantum field theory due to J. Fröhlich and point out some analogies to the classical case. |
| Date: | Tue, 11.12.2012 |
| Time: | 14:15 |
| Location: | Erwin Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock |
| Contact: | J. Yngvason |
| The wave equation on the extreme Reissner-Nordstroem black hole |
| Speaker: | Sergio Dain (Cordoba) |
| Abstract: | joint seminar with the ESI workshop on dynamics on general relativity |
| Date: | Wed, 12.12.2012 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | ESI Erwin Schrödinger Institut, Boltzmanngasse 9, 2. Stock, 1090 Wien |
| Contact: | P. Chrusciel |
| Kaon Decays in the Standard Model |
| Speaker: | Helmut Neufeld (Univ.Wien) |
| Abstract: | im Rahmen des Teilchenphysikseminars |
| Date: | Thu, 13.12.2012 |
| Time: | 14:15 |
| Duration: | 60 min |
| Location: | Fakultät für Physik, Erwin Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock |
| Contact: | G. Ecker |
| The physics of nano-carbons explored by high-resolution electron microscopy |
| Speaker: | Jannik Meyer (Univ.Wien) |
| Abstract: | im Rahmen der gemeinsam veranstalteten Seminare "Komplexe Stochastische Systeme" (Univ.Wien) und "Analyse Komplexer Systeme" (Med.Univ.Wien) |
| Date: | Fri, 14.12.2012 |
| Time: | 14:15 |
| Duration: | 45 min |
| Location: | Fakultät für Physik, Erwin Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock |
| Contact: | H. Hüffel, Stefan Thurner |
| STM on free standing graphene membranes |
| Speaker: | Franz Eder (Univ.Wien) |
| Abstract: | im Rahmen der gemeinsam veranstalteten Seminare "Komplexe Stochastische
Systeme" (Univ.Wien) und "Analyse Komplexer Systeme" (Med.Univ.Wien) |
| Date: | Fri, 14.12.2012 |
| Time: | 15:00 |
| Duration: | 45 min |
| Location: | Fakultät für Physik, Erwin Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock |
| Contact: | H. Hüffel, Stefan Thurner |
|