aspuru-list November 2013

aspuru-list@lists.fas.harvard.edu

34 participants
83 discussions

[Aspuru-Guzik group list] ITAMP topical lunch discussion: Thursday November 7 @ 12:00 *NEW LOCATION*

by tony.lee＠cfa.harvard.edu

Dear Friends, On Thursday, November 7, there will be an ITAMP topical lunch discussion. B-106 Conference Room @ CfA (60 Garden Street) NOTE: ALL FUTURE LUNCH DISCUSSIONS WILL BE HELD IN B-106. Directions: after entering the lobby of the CfA, turn right to enter the hallway of the B building. In the hallway, turn right again, and B-106 is there. Time: 12:00-1:30 As always pizza will be served. Speaker: Vladimir M. Stojanovic Title: Analog quantum simulators of small-polaron physics Abstract: The small-polaron problem – an excess carrier (electron or a hole) heavily dressed in a cloud of virtual phonons due to a self-induced deformation of the host-crystal lattice – is typically addressed within the framework of the Holstein molecular-crystal model. In this talk, two analog quantum simulators for the one-dimensional version of this model will be discussed, based on arrays of trapped ions and superconducting transmon qubits as their respective physical platforms [1,2]. We show that in both cases the strong excitation-phonon coupling regime – characterized by small-polaron formation – can be reached using realistic values of the underlying-system parameters. We propose state-preparation schemes, as well as experimental probes for validating the polaronic character of the phonon-dressed excitations, in both physical platforms. We perform a comparative analysis of the two realizations of the Holstein model, and conclude by underlining their potential use for studying the dynamics of small-polaron formation and density-driven destabilization of such excitations. [1] V. M. Stojanovic, T. Shi, C. Bruder, and J. I. Cirac, Phys. Rev. Lett. 109, 250501 (2012). [2] F. Mei, V. M. Stojanovic, I. Siddiqi, and L. Tian, arXiv:1307.0906. Looking forward to seeing you there, Tony Lee

10 years, 5 months

[Aspuru-Guzik group list] [IACS-events] REMINDER: IACS Seminar featuring Ben Vigoda on Friday, November 8

by Baker, Natasha

Date: Friday, November 8 Location: Maxwell-Dworkin G115, 33 Oxford Street, Cambridge, MA 02138 Speaker: Ben Vigoda, Director, Analog Devices Lyric Labs Time: Informal lunch with speaker, 12:30pm; Talk, 1:00pm. Title: Probabilistic Programming and Probability Processing Abstract: We are developing a computing stack for Bayesian inference and machine learning, including integrated circuits, probabilistic programming languages, compilers, and applications. Our first probability processor hardware demonstrates orders of magnitude wins on machine learning and statistical inference benchmarks. We are developing open-source probability programming languages that help enable rapid prototyping and development of statistical machine learning applications. We will demonstrate some applications that we are building on top of the probability processing stack. Speaker bio: Ben Vigoda is the director of Analog Devices Lyric Labs, a corporate research lab located in Kendall Square, Cambridge that grew from the acquisition by Analog Devices of Lyric Semiconductor, Inc. Lyric was selected as one of the 50 Most Innovative Companies by Technology Review in 2010. The company's work on probability processors has been featured in the Wall Street Journal, New York Times, Wired, and EE Times. ************************* Upcoming IACS Seminar The final IACS seminar of the fall semester will be held on Friday, 11/22. Hugo Larochelle, Assistant Professor at the Université de Sherbrooke, will present on "Deep Learning for Distribution Estimation." Please visit http://iacs.seas.harvard.edu/events to subscribe to our Google calendar, manage your subscription to this mailing list, or access video and audio recordings of previous seminars. _______________________________________________ Iacs-events mailing list Iacs-events(a)seas.harvard.edu https://lists.seas.harvard.edu/mailman/listinfo/iacs-events

10 years, 5 months

[Aspuru-Guzik group list] [qip] Friday the 8th

by Edward Farhi

Hi Quanta We will meet on Friday at 11:00 in 6-310. Borzu Toloui will tell us about how the lack of symmetry can be a quantum resource. Also David Gosset will tell us about stuff he is thinking about beyond his talk which will take place at 1:30 in 6c-442. See you then. Eddie ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: Edward Farhi Cecil and Ida Green Professor of Physics Director Center for Theoretical Physics Massachusetts Institute of Technology 6-300 Cambridge MA 02139 617 253 4871 ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: _______________________________________________ qip mailing list qip(a)mit.edu http://mailman.mit.edu/mailman/listinfo/qip

10 years, 5 months

[Aspuru-Guzik group list] Fwd: Opinions.

by Marlon Cummings

---------- Forwarded message ---------- From: "Alan Aspuru-Guzik" <alan(a)aspuru.com> Date: Nov 6, 2013 9:58 PM Subject: Opinions. To: "aspuru.staff" <aspuru.staff(a)gmail.com> Dear all, Thanks to you all for attending the talks of Brett Savoie and of Jorge Aguilera-Iparraguirre as well as meeting them. Could you send me your honest opinion about your interaction with the candidates? Best, Alan Alán Aspuru-Guzik | Professor of Chemistry and Chemical Biology Harvard University | 12 Oxford Street, Room M113 | Cambridge, MA 02138 (617)-384-8188 | http://aspuru.chem.harvard.edu | http://about.me/aspuru

10 years, 5 months

[Aspuru-Guzik group list] [Aspuru-meetings-list] Peter Love group meeting cancelled, talk by Ville Bergholm on Friday

by Ryan Babbush

Hello Everyone, Due to the unusual number of visitors and guests giving group meetings this week we have decided to cancel Peter Love's group meeting planned for tomorrow at 2:30 in favor of Peter presenting next Thursday. After Jacob Biamonte's group meeting at 2:30pm on Friday (in the Division Room), Dr. Ville Bergholm (a former Aspuru-Guzik group member) will be presenting on recent work he has done involving the quantum control of NV centers. An abstract and title for Ville's talk is included below. =========================================== High fidelity spin entanglement using optimal control =========================================== Precise control of quantum systems is of fundamental importance for quantum device engineering, such as is needed in the fields of quantum information processing, high-resolution spectroscopy and quantum metrology. When scaling up the quantum registers in such devices, several challenges arise: individual addressing of qubits in a dense spectrum while suppressing crosstalk, creation of entanglement between distant nodes, and decoupling from unwanted interactions. The experimental implementation of optimal control is a prerequisite to meeting these challenges. Using engineered microwave pulses, we experimentally demonstrate optimal control of a prototype solid state spin qubit system comprising thirty six energy levels. The spin qubits are associated with proximal nitrogen-vacancy (NV) centers in diamond. We demonstrate precise single-electron spin qubit operations with an unprecedented fidelity F \approx 0.99 in combination with high-efficiency storage of electron spin states in a nuclear spin quantum memory. Matching single-electron spin operations with spin-echo techniques, we further realize high-quality entangled states (F > 0.82) between two electron spins on demand. After exploiting optimal control, the fidelity is mostly limited by the coherence time and imperfect initialization. Errors from crosstalk in a crowded spectrum of 8 lines as well as detrimental effects from active dipolar couplings have been simultaneously eliminated to unprecedented extent. Finally, by entanglement swapping to nuclear spins, nuclear spin entanglement over a length scale of 25 nm is demonstrated. This experiment underlines the importance of optimal control for scalable room temperature spin-based quantum information devices. -- Ryan Babbush | PhD Student in Physics (949) 331-3943 | babbush(a)fas.harvard.edu Harvard University | Aspuru-Guzik Group 12 Oxford Street | Cambridge, MA 02138 _______________________________________________ Aspuru-meetings-list mailing list Aspuru-meetings-list(a)lists.fas.harvard.edu https://lists.fas.harvard.edu/mailman/listinfo/aspuru-meetings-list

10 years, 5 months

[Aspuru-Guzik group list] Let's Welcome Leonardo Pachon (Arrives Tomorrow)

by Marlon Cummings

Dear all, This is Leonardo A Pachon and I'm joining Alan's group as a short-term postdoc from November to April. Following Marlon's suggestion, I want to briefly introduce myself. I received my bachelor in Physics from Universidad Industrial de Santander (Colombia) in 2005. At that time, I started working on relativistic astrophysics and general relativistic effects such as inertial frame dragging. I keep working on this and look forward to make connections with astrochemistry. In 2010 I received my PhD from Universidad Nacional de Colombia. In the first half of my PhD I was mainly focused on the classical-quantum transition of chaotic systems in terms of the phase-space structures. In the second part, I studied the survival of quantum features such as entanglement in out-of-equilibrium quantum systems and extended the Feynman and Vernon approach to phase space. >From Sep 2010-Agu 2011 and Nov 2012-Nov 2013 I worked at University of Toronto as a postdoc in the group of Prof. Paul Brumer. During this time I was devoted to the study of the interplay between quantum systems and their environments. In particular, I was interested in (i) the extend to which quantum coherence can be preserved, (ii) environmentally assisted on-photon phase control and (iii) quantum thermodynamics. From Sep 2011-Oct 2012 I worked at Universidad de Antioquia (Colombia) as a lecturer. My present research interests include relativistic astrophysics, general relativistic effects, non–equilibrium open quantum systems, semi classical approaches in phase space and foundations of quantum mechanics. I look forward to learn from you and contribute to the group, Leonardo

10 years, 5 months

[Aspuru-Guzik group list] Matthias Troyer - Nov. 6 - HQOC/ITAMP Joint Quantum Sciences Seminar

by Hamilton, Joan

**HQOC/ITAMP Joint Quantum Sciences Seminar** ***Wed, Nov. 6th, 4:00 PM, Jefferson 250*** ****Matthias Troyer, ETH**** Quantum Annealing Quantum annealing - a finite temperature version of the quantum adiabatic algorithm - combines the classical technology of slow thermal cooling with quantum mechanical tunneling, to try bring a physical system faster towards its ground state. The Canadian company D-Wave systems has recently built and sold programmable devices that are designed to use this effect to find solutions to hard optimization problems. I will present results of experiments designed to shed light on crucial questions about these controversial devices: are they quantum or classical? And are they faster than classical devices? Joan Hamilton Faculty Assistant to Profs. Greiner and Lukin HQOC Laboratory Administrator HUCTW Local Union Representative Harvard University Department of Physics 17 Oxford Street Cambridge, MA 02138 P: (617) 496-2544 F: (617) 496-2545

10 years, 5 months

[Aspuru-Guzik group list] -- Special AAG group meeting: TODAY, 1:30 pm, Division Room.

by Er, Suleyman

Dear all, Dr. Jorge Aguilera-Iparraguirre's talk is TODAY at 1:30 in the Division room. - Please be there and ask plenty of questions during the presentation. - There is 1 open window at 11:30 due to a last-minute cancellation. This person will be rewarded with a FREE lunch :) Let me know if you can. - Attached is his updated schedule. "EXPLICITLY-CORRELATED METHODOLOGIES IN THE SEARCH FOR ALTERNATIVE FUELS: THE KORCEK REACTION AND MORE." Abstract: This talk will attempt to explain a three point process: First, the importance of kinetic modeling in the study of alternative fuels. Second, how the implementation of automatic computer generation has had a great impact in the reliability and usability of such models, and third, how the set of explicitly-correlated methods available nowadays (in particular CCSD(T)-F12) has made possible to fill the gaps in accuracy that the kinetic methods have lacked in the pass. As the main topic of the talk, the re-discovery of the Korcek reaction. The subject of our latest research. Using very different techniques, from multireference to explicit- correlated calculations, from Transitions State Theory to liquid phase, all in search for an answer to a thirty years old question. Best, Suleyman Süleyman Er, PhD http://aspuru.chem.harvard.edu/suleyman-er/

10 years, 5 months

[Aspuru-Guzik group list] [theochem-announce] Theoretical chemistry seminar TODAY: Prof. Robert Harrison, Stony Brook University

by Michael Mavros

Hi all, Professor Robert Harrison of Stony Brook University / Brookhaven National Lab will be giving a theoretical chemistry seminar *today, November 6 at 4:00 PM in room 4-163.* *Title: Seeking a sustainable model for scientific simulation* *Abstract:* Many are now questioning whether our current approaches to developing software for science and engineering are sustainable. In particular, can we deliver to society and the nation the full benefits expected from high-performance simulation at the peta and exascales? Or is innovative science being stifled by the increasing complexities of all aspects of our problem space (rapidly changing hardware, software, multidisciplinary physics, etc.)? Focusing on applications in chemistry and materials science, and motivated co-design of exascale hardware and software, I will discuss many of these issues including how chemistry has already been forced to adopt solutions that differ quite sharply to those in the mainstream, and how these solutions position us well for the technology transitions now under way. Radical changes in how we compute, going all the way back to the underlying numerical representation and algorithms used for the simulation, also promise great enhancements to both developer productivity and the accuracy of simulations. We hope you can attend! -- Michael Mavros Van Voorhis Group Department of Chemistry, Massachusetts Institute of Technology _______________________________________________ theochem-announce mailing list theochem-announce(a)mit.edu http://mailman.mit.edu/mailman/listinfo/theochem-announce

10 years, 5 months

[Aspuru-Guzik group list] Experimental verification of quantum computation

by sarah mostame

10 years, 5 months

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aspuru-list November 2013