aspuru-list May 2017

aspuru-list@lists.fas.harvard.edu

18 participants
54 discussions

[Aspuru-Guzik Group List] [qip] no group meeting tomorrow

by Aram Harrow

Dear quanta, We will not have a group meeting tomorrow since enough people seem to want to go to this talk (announcement below) instead. It is not quantum, but has relevance to computing amplitudes of quantum circuits. Next week we will have Marcus Appleby tell us about the SIC-POVM problem and algebraic number theory. -aram ---------- Forwarded message ---------- *STOCHASTICS AND STATISTICS SEMINAR* *|* *FRIDAY, March 3 11AM-12PM in Room E18-304 * https://stat.mit.edu/events/alexander-barvinok-u-michigan/ https://whereis.mit.edu/?go=E18 *Title: * Computing partition functions by interpolation *Speaker: * Alexander Barvinok (UMICH) http://www.math.lsa.umich.edu/~barvinok/ *Abstract:* Partition functions are just multivariate polynomials with great many monomials enumerating combinatorial structures of a particular type and their efficient computation (approximation) are of interest for combinatorics, statistics, physics and computational complexity. I’ll present a general principle: the partition function can be efficiently approximated in a domain if it has no complex zeros in a slightly larger domain, and illustrate it on the examples of the permanent of a matrix, the independence polynomial of a graph and, time permitting, the graph homomorphism partition function. *Bio:* Alexander Barvinok is a professor of mathematics at the University of Michigan, Ann Arbor. He is interested in computational complexity and algorithms in algebra, geometry and combinatorics. _______________________________________________ qip mailing list qip(a)mit.edu http://mailman.mit.edu/mailman/listinfo/qip

6 years, 7 months

[Aspuru-Guzik Group List] Group meeting, Thu June 01, 3:30 PM, Div Room

by Ian Kivlichan

Hi all, Tomorrow Nico will talk at group meeting. His title and abstract are below. All the best, Ian ----------------- *Title*: A universal set of binary gates for organic exciton processing and signaling. *Abstract*: The ability to precisely control the movement of excitations can aid in the design of excitonic circuits, with potential applications in bioimaging, microscopic signaling, or new forms of solar energy capture. Here, we demonstrate theoretically that an organic single-molecule exciton "transistor," or exciton gate, can be designed through the careful use of second excited singlet states (S2 states). This design makes it possible to control the direction and distance that an exciton travels, by using either an external light source or an auxiliary exciton source for control. We demonstrate how to overcome the two main obstacles for the strategy to be viable. First, molecules with long-lived S2 states must be used, which limits the design to a small subset of possible molecules. Second, exquisite control of the relative orientations of molecules is required to properly align transition dipole moments, necessitating the use of a nanodesign method such as DNA origami. We introduce a rate model that relates decay rates and orientational errors to the probability that the exciton gate produces false positives and false negatives. Finally, in analogy to traditional transistors, we show how a universal set of logical binary gates may be constructed with these exciton gates, demonstrating that universal computation becomes possible.

6 years, 10 months

[Aspuru-Guzik Group List] Seminar Kochise Bennett: Friday 4pm-5:30pm

by Christoph Kreisbeck

Hi everyone, Kochise Bennett will give a Seminar on Friday at 4pm-5:30pm. We'll be in *Mallinckrodt 217* (in the Department Center). Please find below Kochise's title and abstract. Cheers Christoph title: Ultrafast X-ray Diffraction in Single-Molecules: Signatures of Electronic Coherence abstact: Ultrafast time-resolved X-ray scattering made possible by novel light sources provides a wealth of information about electronic and nuclear molecular dynamical processes. The technique goes beyond merely revealing the time dependent electronic charge density traditionally used in structure determination, also monitoring the interplay of elastic and inelastic processes, nonadiabatic dynamics and electronic coherences. The various ground and excited state contributions to ultrafast diffraction from molecules in crystals, in the gas phase, and from single molecules are surveyed and illustrated by excited state nonadiabatic dynamics simulations of NaF.

6 years, 10 months

[Aspuru-Guzik Group List] Friday, 06/02

by Felixander Negron

Good morning, I will be out of the office this Friday, June 2nd. If anyone needs my assistance, please be sure to see me before end of day tomorrow. Thanks, Felix *Felixander Negron* *Laboratory Administrator * *Aspuru-Guzik Group* *Harvard University **Department of Chemistry and Chemical Biology* *12 Oxford St. M 136* *Cambridge, MA 02138* *P:** (617) 496-9964** F: **617-496-9411*

6 years, 10 months

[Aspuru-Guzik Group List] Visit of Bharath Ramsundar on May 31

by Florian Hase

Hi everyone, we will have Bharath Ramsundar visiting our group on Wednesday, May 31. Bharath is a CS graduate student in the group of Vijay Pande at Stanford working on Machine Learning for drug discovery (http://rbharath.github.io/about/) and would be especially interested in meeting people from Machine Learning and Quantum Machine Learning. He is one of the authors of the recent paper on atomic convolutional networks (https://arxiv.org/abs/1703.10603). Please let me know if you are interested in meeting Bharath. We also have a few lunch spots available. Cheers Flo

6 years, 10 months

[Aspuru-Guzik Group List] Visit of Kochise Bennett on June 2

by Christoph Kreisbeck

Hi everyone, this Friday (June 2nd) Kochise Bennett from the Univerity of California, Irvine is visiting our group. If you would like a meeting with him, please let me know. There are still a few open slots. Kochise did his Ph.D. with Shaul Mukamel and has diverse research interests which range from spectroscopy, excitonics, quantum field effects (spectroscopy with quantum light), etc. see also his publications https://scholar.google.com/citations?user=WZCUsokAAAAJ&hl=en Cheers Christoph

6 years, 10 months

[Aspuru-Guzik Group List] CCB Closing at 2:30 PM Today for Memorial Day Weekend

by Siria Serrano

Dear Group, A heads up that the department is closing at 2:30 PM today for the Memorial Day weekend. We'll be back on Tuesday! Cheers, Siria -- *Siria Serrano* *Faculty Assistant* *Aspuru-Guzik Group* *Harvard University **Department of Chemistry and Chemical Biology* *12 Oxford St. M 136* *Cambridge, MA 02138* *P:** (617) 496-1716 <%28617%29%20496-1716>** F: **617-496-9411 <617-496-9411>*

6 years, 11 months

[Aspuru-Guzik Group List] [qip] Group meeting tomorrow

by Aram Harrow

Ted Yoder will speak about his recent work on FTQC. Aram _______________________________________________ qip mailing list qip(a)mit.edu http://mailman.mit.edu/mailman/listinfo/qip

6 years, 11 months

[Aspuru-Guzik Group List] Group meeting, Thu May 25, 3:30 PM, Div Room

by Ian Kivlichan

Hi all, Tomorrow Roland Lindh and his postdoc Morgane Vacher will talk at group meeting. Morgane's title and abstract are included below and Roland's are attached. Best, Ian ----------------- Speaker: Morgane Vacher Title: Electron Dynamics upon Ionization of Polyatomic Molecules: Coupling to Quantum Nuclear Motion and Decoherence Abstract: Knowledge about the electronic motion in molecules is essential for our understanding of chemical reactions and biological processes. The advent of attosecond techniques opens up the possibility to induce electronic motion, observe it in real time, and potentially steer it. A fundamental question remains the factors influencing electronic decoherence and the role played by nuclear motion in this process. Here, we simulate the dynamics upon ionization of the polyatomic molecules paraxylene and modified bis-methylene-adamantane, with a quantum mechanical treatment of both electron and nuclear dynamics using the direct dynamics variational multiconfigurational Gaussian method. These simulations give new important physical insights about the expected decoherence process. In particular, we show that the decoherence of electron dynamics happens on the time scale of a few femtoseconds, with the interplay of different mechanisms: the dephasing is responsible for the fast decoherence while the nuclear overlap decay may actually help maintain it and is responsible for small revivals.

6 years, 11 months

[Aspuru-Guzik Group List] ITAMP workshop on Frontiers of Interacting Systems of Rydberg Atoms - June 1 & 2

by Ploucha, Clare

Dear All: We would like to invite you to the ITAMP workshop on "Frontiers of Interacting Systems of Rydberg Atoms" to be held in the Pratt conference room at 60 Garden St. on June 1 and 2, 2017. There's no registration fee for the local participants, but for us to account for the number of attendees, we ask you to visit https://www.cfa.harvard.edu/itamp-event/frontiers-interacting-systems-rydbe… and click on the Registration link. Please choose the "payment by check" option, and pick a random check number so that you can complete the registration process. We look forward to seeing you soon at ITAMP. Regards Naomi -- Naomi Tariri Program Coordinator The Institute for Theoretical Atomic, Molecular and Optical Physics 60 Garden Street, MS 14 Cambridge MA 02138 617-495-9524<tel:(617)%20495-9524> | http://www.cfa.harvard.edu/itamp/

6 years, 11 months

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aspuru-list May 2017