aspuru-list January 2017

aspuru-list@lists.fas.harvard.edu

18 participants
47 discussions

[Aspuru-Guzik Group List] Excitonics Seminar: Tues. Feb 7, 4:30 pm in 36-428

by Catherine M Bourgeois

CENTER FOR EXCITONICS SEMINAR SERIES: Nano- and single-crystals of lead halide perovskites: from bright light emission to hard radiation detection February 7, 2017 at 4:30pm/36-428 RLE Haus Room Maksym Kovalenko ETH Zurich, Department of Chemistry [http://www.rle.mit.edu/excitonics/wp-content/uploads/2016/06/Kovalenko4-1-2…] Chemically synthesized inorganic nanocrystals (NCs) are considered to be promising building blocks for a broad spectrum of applications including electronic, thermoelectric, and photovoltaic devices. We have synthesized monodisperse colloidal nanocubes (4-15 nm edge lengths) of fully inorganic cesium lead halide perovskites (CsPbX3, X=Cl, Br, and I or mixed halide systems Cl/Br and Br/I) using inexpensive commercial precursors [1]. Their bandgap energies and emission spectra are readily tunable over the entire visible spectral region of 410-700 nm. The photoluminescence of CsPbX3 NCs is characterized by narrow emission line-widths of 12-42 nm, wide color gamut covering up to 140% of the NTSC color standard, high quantum yields of up to 90% and radiative lifetimes in the range of 4-29 ns. Post-synthestic chemical transformations of colloidal NCs, such as ion-exchange reactions, provide an avenue to compositional fine tuning or to otherwise inaccessible materials and morphologies. While cation-exchange is facile and commonplace, anion-exchange reactions have not received substantial deployment. We observed fast, low-temperature, deliberately partial or complete anion-exchange in CsPbX3 NCs. By adjusting the halide ratios in the colloidal NC solution, the bright photoluminescence can be tuned over the entire visible spectral region (410-700 nm). Furthermore, fast inter-NC anion-exchange is demonstrated as well, leading to uniform CsPb(Cl/Br)3 or CsPb(Br/I)3 compositions simply by mixing CsPbCl3, CsPbBr3 and CsPbI3 NCs in appropriate ratios. We also present low-threshold amplified spontaneous emission and lasing from CsPbX3 NCs [3]. We find that room-temperature optical amplification can be obtained in the entire visible spectral range (440-700 nm) with low pump thresholds down to 5±1 µJ cm-2 and high values of modal net gain of at least 450±30 cm-1. Two kinds of lasing modes are successfully realized: whispering gallery mode lasing using silica microspheres as high-finesse resonators, conformally coated with CsPbX3NCs, and random lasing in films of CsPbX3 NCs. We also demonstrated that 0.3-1 cm, solution-grown single crystals (SCs) of semiconducting hybrid lead halide perovskites (MAPbI3, FAPbI3 and I-treated MAPbBr3, where MA=methylammonium, FA=formamidinium) can serve as solid-state gamma-detecting materials detectors (e.g. for direct sensing of photons with energies as high as mega-electron-volts, MeV) [4]. This possibility arises from a high mobility(µ)-lifetime(τ) product of 1.0-1.8 10-2 cm2 V-1, low dark carrier density of 109 – 1011 cm-3 and low density of charge traps of 109 – 1010 cm-3, and a high absorptivity of hard radiation by the lead and iodine atoms. We demonstrated the utility of perovskite detectors for testing the radio-purity of medical radiotracer compounds such as 18F-fallypride. Energy-resolved sensing at room temperature is presented using FAPbI3 single crystals (SCs) and an 241Am source. With FAPbI3SCs, that amongst all tested crystals exhibit highest mobility-lifetime product and lowest noise levels and dark currents, a portable dosimetry prototype is demonstrated. [http://www.rle.mit.edu/excitonics/wp-content/uploads/2016/06/kovalenko-r-im…]<http://www.rle.mit.edu/excitonics/wp-content/uploads/2016/06/kovalenko-r-im…> 1. Protesescu et al. Nano Letters 2015, 15, 3692–3696 2. Nedelcu et al. Nano Letters 2015, 15, 5635–5640 3. Yakunin et al. Nature Communications 2015, 9, 8056. 4. Yakunin et al. Nature Photonics 2016, doi:10.1038/nphoton.2016.139 Maksym V. Kovalenko has been tenure-track Assistant Professor of Inorganic Chemistry at ETH Zürich (Swiss Federal Institute of Technology) since July 2011. His group is also partially hosted by Empa (Swiss Federal Laboratories for Materials Science and Technology) to support his highly interdisciplinary research program. He studied chemistry in Ukraine (1999-2004, Chernivtsi National University). His doctoral studies took place in Austria (2004-2007, Institute of Solid State Physics, Johannes Kepler University, Linz, with Prof. Wolfgang Heiss). He then moved to USA (2008-2011, Department of Chemistry, University of Chicago, with Prof. Dmitri Talapin). His present scientific focus is on the development of new synthesis methods for inorganic nanomaterials, their surface chemistry and assembly into macroscopically large solids. His ultimate, practical goal is to provide novel inorganic materials for photonics and optoelectronics, as well as for rechargeable Li-ion batteries and post-Li-electrochemistries. Recently, his group pioneered the synthesis of highly luminescent colloidal nanomaterials of cesium lead halide perovskites, which hold great potential for applications in display technologies and for lighting. With much larger forms of lead halide perovskites – inch-sized single-crystals – he recently demonstrated sensitive detection of hard radiation (hard X-rays and gamma photons). He is the recipient of an ERC Starting Grant 2012, Ruzicka Preis 2013 and Werner Prize 2016. He published over 110 articles in peer-reviewed journals, co-authored 3 book chapters, and is listed as inventor in 8 patents. Research<http://www.old-lac.ethz.ch/kovalenko/people_professor.html> The Center For Excitonics Is An Energy Frontier Research Center Funded By The U.S. Department Of Energy, Office Of Science And Office Of Basic Energy Sciences Light refreshments will be served.

7 years, 2 months

[Aspuru-Guzik Group List] Fwd: postdoc position

by Alan Aspuru-Guzik

---------- Forwarded message --------- From: Balu, Radhakrishnan CIV USARMY RDECOM ARL (US) < radhakrishnan.balu.civ(a)mail.mil> Date: Tue, Jan 31, 2017 at 3:21 PM Subject: RE: postdoc position To: alan(a)aspuru.com <alan(a)aspuru.com> Dear Alan, We have a postdoc position opened up in our branch and if you know someone looking for a position please refer them to me. The project will be on computational aspects of open quantum systems solving quantum stochastic differential equations numerically to obtain trajectories of master equations. I can give more details over the phone. With Best Wishes Rad Radhakrishnan Balu, Ph.D Computer Scientist (Quantum Sciences) High Performance Computing Network Branch Computational & Info Sciences Directorate US Army Research Lab, MD ☎ (301) 394 4302 (ALC) Email: radhakrishnan.balu.civ(a)mail.mil -- Alán Aspuru-Guzik | Professor of Chemistry and Chemical Biology Harvard University | 12 Oxford Street, Room M138 | Cambridge, MA 02138 (617)-384-8188 | http://aspuru.chem.harvard.edu | http://about.me/aspuru

7 years, 2 months

[Aspuru-Guzik Group List] Group meeting Thursday at 2:30 this week

by Ian Kivlichan

Hi all, Just an early heads up that group meeting this week will be at 2:30 PM on Thursday, rather than the usual 3:30 PM. (Still in the Div Room.) I'll send out the title and abstract tomorrow. Best, Ian

7 years, 2 months

[Aspuru-Guzik Group List] Fwd: Science of Physical Universe 13 - TFs needed

by Alan Aspuru-Guzik

Dear all, Please see the advertisement for teaching fellows for Rick Heller's course. It may be of interest and Rick is a terrific instructor. I encourage you all to consider it. Let me and Felix know if you apply for the job Alan Alán Aspuru-Guzik | Professor of Chemistry and Chemical Biology | Harvard University 12 Oxford Street, Room M113 | Cambridge, MA 02138 (617)-384-8188 <(617)%20384-8188> | http://aspuru.chem.harvard.edu ---------- Forwarded message ---------- From: Lavin, Joe <lavin(a)chemistry.harvard.edu> Date: Tue, Jan 31, 2017 at 9:52 AM Subject: Science of Physical Universe 13 - TFs needed To: "Aspuru-Guzik, Alan" <aspuru(a)chemistry.harvard.edu> Hi Alan, Here's the Heller course that still needs TFs He's looking to fill two sections, so it could be either quarter- or half-time. He writes that " they need to be musically or acoustically at least somewhat inclined." If you could check with your group, that would be great. Thanks, Joe Science of Physical Universe 13 Why You Hear What You Hear: The Science of Music and Sound Mon, Wed 2:30-4:00 Sound and music are integral parts of all human cultures, and play critical roles in communications and social interactions. In this course, we study the production, transmission, and perception of sound, with the aim of expanding communication, musical, and artistic horizons. The course includes many class demos and hands on tools for students to explore. Psychoacoustics (the study of how we perceive and interpret sound) is a central theme of the course, providing a lens through which we can better understand the generation, propagation, and analysis of sound. Student-selected projects (with staff consultation) are an important part of the course. Joe Lavin Associate Director of Academic Affairs Chemistry and Chemical Biology, Harvard University 12 Oxford Street - Mallinckrodt 133A, Cambridge, MA 02138 (617) 496-3209, lavin(a)chemistry.harvard.edu

7 years, 2 months

[Aspuru-Guzik Group List] Quantum Gigs at Rigetti Computing

by Dorsk, Alexander

For those who dig quantum computing/software, gig posting below from a classmate of mine (spike(a)spikecurtis.com). -Alex Hi Alums! Can I tempt any of you to come help me build the world's most powerful computer (and change computer engineering forever)? I'm at Rigetti Quantum Computing in Berkeley, CA. We recruiting software, mechanical, RF, and nano-fabrication engineers. I'm personally looking to find a full-stack web engineer <https://jobs.lever.co/rigetti/fd6715c9-99fd-4295-b843-c42d8299e18d> (build deeply quantitative analysis tools for physicists) and someone to work with me on building a Quantum OS <https://jobs.lever.co/rigetti/aaf7589f-9e9e-4be9-aedb-c7d3b4ab5994>. Full jobs page is here. <https://jobs.lever.co/rigetti> Email me if you are interested! I'm happy to chat. Spike Curtis '06

7 years, 2 months

[Aspuru-Guzik Group List] [qip] group meetings + probability class

by Aram Harrow

Dear quanta, 1. Let's restart group meetings this Friday, Feb 3 at 11am in room 6-310, like in the good old days, but with donuts + coffee starting a bit earlier. The agenda is: everyone who went to QIP talk about something interesting they learned there. Also, please think about whether you'd like to speak about your work in some future group meeting or if you want to nominate someone else to talk about their work. 2. Besides 6.443/8.37/118.436, there is another class on just the subfield of quantum information concerning diagonal density matrices. This esoteric special case is also called "probability." This class looks pretty good. Subject: 6.265 Modern Discrete Probability Time: MW 1-2:30p in 56-154 Instructors: Guy Bresler and Yury Polyanskiy Description: This class was developed for those planning to work on discrete probabilistic systems arising in modern statistics and CS. The class will be at a level appropriate for first-year graduate students and aspiring undergraduates. The topics are motivated by and applied to several foundational models: percolation, random graphs, and Ising model, as well as dynamics on them and associated computational problems. A central theme is the study of sharp thresholds. Prerequisites: 6.436 or equivalent (measure-theoretic probability will not be needed) Syllabus and more info in the attached pdf. _______________________________________________ qip mailing list qip(a)mit.edu http://mailman.mit.edu/mailman/listinfo/qip

7 years, 2 months

[Aspuru-Guzik Group List] Class Permission

by Felixander Negron

Good morning, To those individuals that were experiencing problems with registering for class last week, I just received an e-mail from Joe Lavin to make me aware that he approved everyone on Friday. If you are still having issues, please let me know. 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*

7 years, 2 months

[Aspuru-Guzik Group List] [qip] postdoc opening in Berlin

by Aram Harrow

Dear quanta, It looks like group meetings will be back on Fridays at 11. We will start either next week or the week after, depending on interest. Also, see below for a job ad: Postdoctoral position in condensed matter and quantum information theory We are currently offering an (extendable) 3-year postdoctoral position to a highly motivated and well-qualified young researcher who intends to enhance his or her career on the intersection of condensed matter theory and quantum information science. The successful candidate will work as part of the research group led by Jens Eisert at the FU Berlin. For an overview of research activities of the group, see http://www.physik.fu-berlin.de/en/einrichtungen/ag/ag-eisert/research We are a leading research group with a culture of open discussion, creative interdisciplinary thought and substantial international collaborations. Potential research topics include the following: - Tensor network approaches to studying condensed matter systems, - notions of topological order, - entanglement theory, - topological quantum computing and quantum memories. The full E13 position will be financed by the CRC 183 on entangled states of matter, with Berlin, Cologne, Copenhagen, and the Weizmann Institute being partners. This newly installed network will contribute to the stimulating research environment, and all network activities will be available to the candidate. For first activities of this research network, see http://crc183.uni-koeln.de Applicants must have demonstrated excellent research accomplishments in the past. Candidates must hold a PhD degree in physics or mathematics or should obtain such a degree in the near future. Interested candidates are invited to submit - a letter indicating their main research interests, - a detailed curriculum vitae, - a list of publications, - the electronic (email) contact details of three potential referees. All applications should be sent in electronic form to jense(a)physik.fu-berlin.de with the key word "TopologicalBerlin" in the subject line. Review of the applications will begin after February 28, 2017 and will continue until the positions are filled. Early submissions are appreciated. The start date would be the soonest possible. _______________________________________________ qip mailing list qip(a)mit.edu http://mailman.mit.edu/mailman/listinfo/qip

7 years, 2 months

[Aspuru-Guzik Group List] Fwd: Long-term postdoctoral position

by Alan Aspuru-Guzik

Great position outside of the Trumpistan empire. Eisert is perhaps the smartest QI scientist out there. Please spread. ---------- Forwarded message --------- From: Jens Eisert <jenseisert(a)googlemail.com> Date: Fri, Jan 27, 2017 at 9:05 AM Subject: Long-term postdoctoral position To: Jens Eisert <jenseisert(a)gmail.com> Postdoctoral position in condensed matter and quantum information theory We are currently offering an (extendable) 3-year postdoctoral position to a highly motivated and well-qualified young researcher who intends to enhance his or her career on the intersection of condensed matter theory and quantum information science. The successful candidate will work as part of the research group led by Jens Eisert at the FU Berlin. For an overview of research activities of the group, see http://www.physik.fu-berlin.de/en/einrichtungen/ag/ag-eisert/research We are a leading research group with a culture of open discussion, creative interdisciplinary thought and substantial international collaborations. Potential research topics include the following: - Tensor network approaches to studying condensed matter systems, - notions of topological order, - entanglement theory, - topological quantum computing and quantum memories. The full E13 position will be financed by the CRC 183 on entangled states of matter, with Berlin, Cologne, Copenhagen, and the Weizmann Institute being partners. This newly installed network will contribute to the stimulating research environment, and all network activities will be available to the candidate. For first activities of this research network, see http://crc183.uni-koeln.de Applicants must have demonstrated excellent research accomplishments in the past. Candidates must hold a PhD degree in physics or mathematics or should obtain such a degree in the near future. Interested candidates are invited to submit - a letter indicating their main research interests, - a detailed curriculum vitae, - a list of publications, - the electronic (email) contact details of three potential referees. All applications should be sent in electronic form to jense(a)physik.fu-berlin.de with the key word "TopologicalBerlin" in the subject line. Review of the applications will begin after February 28, 2017 and will continue until the positions are filled. Early submissions are appreciated. The start date would be the soonest possible. -- Jens Eisert Professor of Quantum Physics Dahlem Center for Complex Quantum Systems Physics Department Freie Universität Berlin Arnimallee 14, 14195 Berlin jenseisert(a)gmail.com http://www.physik.fu-berlin.de/en/einrichtungen/ag/ag-eisert http://scholar.google.de/citations?user=WawCci0AAAAJ&hl=en -- Alán Aspuru-Guzik | Professor of Chemistry and Chemical Biology Harvard University | 12 Oxford Street, Room M138 | Cambridge, MA 02138 (617)-384-8188 | http://aspuru.chem.harvard.edu | http://about.me/aspuru

7 years, 2 months

[Aspuru-Guzik Group List] Fwd: Prof. Mark Tuckerman, visiting Theochem speaker, Thu Feb 2

by Jennifer Wei

Hi Everyone, Next week we have Prof. Mark Tuckerman of NYU visiting us for Theochem. His talk will Wednesday, Feb. 1, 4:15pm at MIT 4-237 (note room change). See below for the title and abstract. Prof. Tuckerman will be visiting Harvard on Thursday, Feb. 2nd. Please see below for information from Victor Zhao, who is hosting him this visit. If you would like to meet Prof. Tuckerman during his visit to Harvard, please contact Victor directly (cc'ed). Best, Jennifer ---------- Forwarded message --------- From: Victor Zhao <yzhao01(a)g.harvard.edu> Date: Thu, Jan 26, 2017 at 7:47 PM Subject: Prof. Mark Tuckerman, visiting Theochem speaker, Thu Feb 2 To: Jennifer Wei <jenniferwei(a)fas.harvard.edu> Hi Jennifer, Here is the message for the Aspuru-Guzik group. Thanks! Victor ------ Hello all, Prof. Mark Tuckerman of NYU <https://urldefense.proofpoint.com/v2/url?u=http-3A__chemistry.fas.nyu.edu_o…> will be visiting Boston next week. On Wednesday afternoon, he will be giving the Theochem lecture at MIT (details below), and on Thursday Feb 2, he will be at Harvard. I am responsible for organizing his schedule for Thursday. Please let me know if you are available / would like to meet him next Thursday. Additionally, there is opportunity to join him for lunch or dinner, so please let me know if that’s something you would like to attend. My current plan is to have interested members of the Aspuru-Guzik group meet Prof. Tuckerman together at one time, but depending on level of interest, I can also split that up into two meeting groups. Best, Victor Wednesday, Feb 1 4:15 PM MIT, 4-237 Professor Mark Tuckerman New York University “Exploration and learning of free energy landscapes of molecular crystals and oligopeptides” Theory, computation, and high-performance computers are playing an increasingly important role in helping us understand, design, and characterize a wide range of functional materials, chemical processes, and biomolecular/biomimetic structures. The synergy of computation and experiment is fueling a powerful approach to address some of the most challenging scientific problems. In this talk, I will describe the efforts we are making in my group to develop new computational methodologies that address specific challenges in free energy exploration and generation. In particular, I will describe our recent development of enhanced free energy based methodologies for predicting structure and polymorphism in molecular crystals and for determining conformational equilibria of oligopeptides. The strategies we are pursuing include heterogeneous multiscale modeling techniques, which allow “landmark” locations (minima and saddles) on a high-dimensional free energy surface to be mapped out, and temperature-accelerated methods, which allow relative free energies of the landmarks to be generated efficiently and reliably. I will then discuss new schemes for using machine learning techniques

7 years, 2 months

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

aspuru-list January 2017