aspuru-list May 2014

aspuru-list@lists.fas.harvard.edu

31 participants
68 discussions

[Aspuru-Guzik group list] ITAMP topical lunch discussion: Friday, May 23 @ 12:00

by tony.lee＠cfa.harvard.edu

ITAMP Topical Lunch Discussion Date: FRIDAY, May 23 Time: 12:00-1:30 pm Pizza will be served. Location: B-106 @ Center for Astrophysics (60 Garden Street) 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. *Speaker*: Shannon Harvey (Harvard) *Title: *Suppressing Qubit Dephasing using real-time Hamiltonian Parameter Estimation *Abstract: *Electron spins in semiconductor quantum dots hold promise for quantum information processing (QIP) due to their potential for scalability and miniaturization. However, interactions with the fluctuating nuclear spins in the substrate cause these qubits to dephase in tens of nanoseconds. In this talk, I will introduce the singlet-triplet qubit, a type of semiconductor spin qubit, and discuss recent work in which we have used techniques from Hamiltonian parameter estimation to increase the coherence time in these qubits. Using a Bayesian approach, we rapidly estimate the nuclear splitting faster than it fluctuates. We use this estimate to update Hamiltonian control parameters in a way that makes the qubit insensitive to nuclear noise, thereby increasing T2* from tens of nanoseconds to over 2 us. This technique is straightforward to implement and applicable to a wide array of qubits for QIP and metrological purposes.

9 years, 11 months

[Aspuru-Guzik group list] [qip] today, tomorrow

by Edward Farhi

Hi Quanta We will have our usual meeting on Friday at 11:00 in 6-310. Steve Flammia is visiting and will tell us about what he is up to. Also at 1:30 on Friday there will be a seminar by Robin Blume-Kohout and today there is a talk by Nicole Halpern at 4:00. See you at all of these events! Best, Eddie *********************************************** Edward Farhi Cecil and Ida Green Professor of Physics Director Center for Theoretical Physics Massachusetts Institute of Technology Building 6 room 300 Cambridge MA 02139 617 253 4871 *********************************************** _______________________________________________ qip mailing list qip(a)mit.edu http://mailman.mit.edu/mailman/listinfo/qip

9 years, 11 months

[Aspuru-Guzik group list] Aspuru Group Meeting Thursday 22nd at 2:30 pm in Cabot Division Room

by Felipe Herrera

Hi everyone, Tomorrow Lusann Wren Yang will be our guest speaker during our regular group meeting. The title and abstract of her talk are below. Best, Felipe Herrera *Title: *Data Mining Chemistry and Crystal Structure *Abstract:* The availability of large amounts of data generated by high-throughput computing and experimentation has generated interest in the application of machine learning techniques to materials science. Machine learning of materials behavior requires the use of feature vectors that capture compositional or structural information influence a target property. We present methods for assessing the similarity of compositions, substructures, and crystal structures. Similarity measures are important for the classification and clustering of data points, allowing for the organization of data and the prediction of materials properties. The similarity functions between ions, compositions, substructures and crystal structure are based upon a data-mined probability with which two ions will substitute for each other within the same structure prototype. The composition similarity is validated via the prediction of crystal structure prototypes for oxides from the Inorganic Crystal Structure Database. It performs particularly well on the quaternary oxides, predicting the correct prototype within 5 guesses 90% of the time. The sustructural similarity is validated via the prediction of Li insertion sites in the oxides; it finds all of the Li sites with less than 8 incorrect guesses 90% of the time.

9 years, 11 months

[Aspuru-Guzik group list] [qip] Kevin speaking in 10 minutes

by aram harrow

reminder: Kevin will talk about HSP for nilpotent groups at 11am in room 6C-442. upcoming talks also are Nicole Halpern 4pm tomorrow and Robin Blume-Kohout at 1:30pm Friday. Finally, I will also do a bonus talk from 3-3:30pm tomorrow on an epsilon-net version of (some part of) the BCY result. It will be technical and is only recommended for aficionados of the BCY result. (BCY = 1010.1750, but if you didn't already know that, you might find my talk boring.) This talk is also in room 6C-442. aram _______________________________________________ qip mailing list qip(a)mit.edu http://mailman.mit.edu/mailman/listinfo/qip

9 years, 11 months

[Aspuru-Guzik group list] ITAMP topical lunch discussion: Friday, May 23 @ 12:00

by tony.lee＠cfa.harvard.edu

9 years, 11 months

[Aspuru-Guzik group list] Fwd: [ PSI-K ] Professor in Theoretical Chemistry

by Xavier Andrade

---------- Forwarded message ---------- From: "PSI-K" <psik-coord(a)dl.ac.uk> Date: May 20, 2014 5:36 AM Subject: [ PSI-K ] Professor in Theoretical Chemistry To: "PSI-K" <psik-coord(a)dl.ac.uk> Cc: > An announcement has been added in the "PSI-K" site at PSI-K ( http://cselnx9.dl.ac.uk:8080/portal) > > > Subject: Professor in Theoretical Chemistry > > Category: Job > > From: Hans Agren > > Date: 20-May-2014 10:32 > > Message: > > Professor in Theoretical Chemistry at the Royal Institute of Technology, Stockholm, Sweden > > see > > http://www.kth.se/en/om/work-at-kth/vacancies/professor-in-theoretical-chem… > > > > > ---------------------- > This automatic notification message was sent by PSI-K ( http://cselnx9.dl.ac.uk:8080/portal) from the PSI-K site. > You can modify how you receive notifications at My Workspace > Preferences.

9 years, 11 months

[Aspuru-Guzik group list] Fwd: did you see this paper?

by Alan Aspuru-Guzik

FYI to the CEP people. 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 ---------- Forwarded message ---------- From: Alejandro Briseno <abriseno71(a)gmail.com> Date: Mon, May 19, 2014 at 5:25 PM Subject: did you see this paper? To: Alan Aspuru-Guzik <alan(a)aspuru.com> You probably refereed it.. -- Alejandro L. Briseno Assistant Professor Polymer Science and Engineering University of Massachusetts, Amherst Room A213, Conte Research Center 120 Governors Drive, Amherst, MA 01003 Tel: 413.577.1213 / Fax: 413.545.0082 https://www.pse.umass.edu/faculty/researchgroup/briseno

9 years, 11 months

[Aspuru-Guzik group list] [qip] visitors + three talks this week: Wed 11am, Thurs 4pm, Fri 1:30pm

by aram harrow

Dear quanta, We have an exciting roster of speakers and visitors coming up this week. Visitors: Steve Flammia (Sydney): May 20-27 Robin Blume-Kohout (Sandia) : May 22-23 Nicole Yunger Halpern (Caltech): May 22 If you want to meet any of them, either email me, or email them directly. Their office locations are on the blackboard at the entrance of the CTP. Talks, each in 6c-442: Wed, 11am: Kevin Zatloukal (MIT), Subset sum and the hidden subgroup problem for nilpotent groups Thurs, 4pm: Nicole Yunger Halpern, Beyond heat baths: Resource theories for small-scale thermodynamics Fri, 1:30pm: Robin Blume-Kohout, Quantum information is (inconveniently!) a gauge theory There is (inconveniently!) no abstract for the last talk. Abstracts for the first two talks are: 1. Zatloukal - HSP In this talk, we demonstrate that there exists an efficient quantum algorithm for solving the hidden subgroup problem (HSP) in k-nilpotent groups if we are provided with an oracle for solving average-case subset sum. The same fact was already known for the dihedral group. In fact, solving HSP for the dihedral group is thought to be equivalent to solving average-case subset sum. Thus, our result can be interpreted as showing that the HSP for any k-nilpotent group is no harder than the HSP for the dihedral group. Using classical algorithms for solving subset sum (even just the brute-force algorithm), we are able to get a non-trivial speedup for all k-nilpotent groups. In particular, for 2-groups, the subset sum problem is easy, so we get efficient quantum algorithms for k-nilpotent 2-groups. This is an especially interesting case because the dihedral group can be a 2-group as well, albeit one of high nilpotency class. 2. Halpern - thermodynamics How can thermodynamics, which involves vast numbers of particles, describe cutting-edge technology, which involves tiny scales? Heat exchanges have been modeled with the resource-theory framework famous for elucidating entanglement. “Helmholtz” resource theories have shown that the work cost W_cost of creating one copy of a state can differ from the work W_dist distillable from the state. This “one-shot” result contrasts with the thermodynamic limit, in which W_cost = W_dist. I will generalize the resource-theory framework from heat exchanges to more-arbitrary thermodynamic interactions. I will introduce resource theories of non-equilibrium, a family of models that includes the Helmholtz theories. In addition to shedding new light on Helmholtz theories, the non-equilibrium framework expands the resource theories’ potential to describe experiments and quantum phenomena. I will quantify the distinction between W_cost and W_dist in terms of the hypothesis-testing entropy D_H. This research is motivated by the interplay between information and energy on small scales exemplified by single-molecule experiments, nanoscale engines, and molecular motors. This work was conducted partially (arXiv:1309.6586) at the Perimeter Institute for Theoretical physics with Markus Müller and Rob Spekkens, as well as with Gilad Gour and Varun Narasimhachar. Part of this work is being conducted with Joe Renes. _______________________________________________ qip mailing list qip(a)mit.edu http://mailman.mit.edu/mailman/listinfo/qip

9 years, 11 months

[Aspuru-Guzik group list] Vacation

by Marlon Cummings

Dear Friends: I'll be away on Thursday and Friday. Thanks, MC ------------ Marlon G. Cummings Lab Manager, Aspuru-Guzik Group Mallinckrodt M112 Department of Chemistry and Chemical Biology Harvard University 12 Oxford Street Cambridge, MA 02138 617-496-9964 617-496-9411 (fax) http://aspuru.chem.harvard.edu/

9 years, 11 months

[Aspuru-Guzik group list] Fwd: EQuS theory postdoctoral position at the University of Queensland

by Alan Aspuru-Guzik

---------- Forwarded message ---------- From: *Tom Stace* <stace(a)physics.uq.edu.au> Date: Monday, May 19, 2014 Subject: EQuS theory postdoctoral position at the University of Queensland To: SMP physics-all <physics-all(a)lists.smp.uq.edu.au> Cc: Gerard Milburn <g.milburn(a)uq.edu.au> Dear All, I’d be very grateful if you could pass this on to any talented young researchers you know who are looking to build their research careers in a vibrant group in a great part of the world. The UQ node of the ARC Centre of Excellence in Engineered Quantum Systems ( EQuS <http://equs.org>) has just advertised a 3 year postdoctoral research position to conduct theoretical research on quantum measurement, feedback and control; quantum error correction and suppression; and quantum enabled sensors in engineered quantum systems including mechanical, optical and electronic quantum devices. The successful applicant will work closely with Dr Tom Stace and Prof Gerard Milburn at UQ, and will be strongly encouraged to engage with ongoing experimental research efforts within EQuS. The closing date for applications is June 15, 2014. More details are available at: http://jobs.uq.edu.au/caw/en/job/496041/research-fellow-postdoctoral-resear… Regards, Tom ----------------------------- Dr. Tom Stace Department of Physics University of Queensland Brisbane, Australia tel: +61 7 3365 1868 http://www.smp.uq.edu.au/node/106/427 -- 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

9 years, 11 months

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aspuru-list May 2014