{"id":53,"date":"2019-12-17T18:18:12","date_gmt":"2019-12-17T18:18:12","guid":{"rendered":"http:\/\/wp.lancs.ac.uk\/condmat\/?page_id=53"},"modified":"2019-12-17T20:30:52","modified_gmt":"2019-12-17T20:30:52","slug":"summer-term-2018-19","status":"publish","type":"page","link":"https:\/\/wp.lancs.ac.uk\/condmat\/summer-term-2018-19\/","title":{"rendered":"Summer Term 2018\/19"},"content":{"rendered":"\n
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Condensed Matter Theory Group Meetings: Summer 18\/19<\/h2>\n\n\n\n

This term’s meetings will take place at 11am on Thursdays. Please volunteer a talk or make known any masters students who are willing to give talks.<\/p>\n\n\n\n

Dice Seminars:<\/strong>
Sometimes we run Dice Seminars<\/strong>, which occur over the course of 5 weeks or so, and consist of us collaboratively learning about a given topic, by reading a paper or paper section, and rolling a dice to determine who will talk about what they’ve read. The previous topic was “Topological Insulators”, and ran for an extended period. The topic before that was “Weyl Semimetals”.<\/p>\n\n\n\n

Other Meetings:<\/strong>
\u200bThere are ~weekly condensed matter seminars at 3pm on Fridays, <\/strong>which will be interesting for anyone attending our group meetings.  These are advertised internally.<\/p>\n\n\n\n

Mailing List:<\/strong>
If you would like to be added to the mailing list for these meetings, please subscribe<\/a><\/strong> or contact Ryan or Marcin (addresses at page footer). <\/p>\n\n\n\n

Week<\/td>Presenter<\/td>Talk<\/td>Venue<\/td><\/tr>
23
9th May<\/td>		TBR
(To Be Rolled)<\/td>		Dice seminar – machine learning weeks 9-11<\/td>C36<\/td><\/tr>
25
23rd May<\/td>		Henning
Schomerus<\/td>		<\/td>C36<\/td><\/tr>
26
30th May<\/td>		Neil
Drummond<\/td>		Adhesion of graphene to hexagonal boron nitride and gold<\/td>C36<\/td><\/tr>
27
6th June<\/td>		David
Thomas<\/td>		Defect Formation Energies in Graphene<\/td>C36<\/td><\/tr>
28
13th June<\/td>		Marcin
Szyniszewski<\/td>		Entanglement transition from variable-strength weak measurements<\/td>C36<\/td><\/tr>
29
20th June<\/td>		Ryan Hunt &
Yassmin Asiri<\/td>		<\/td>A7<\/td><\/tr>
30
27th June<\/td>		Tom Simons<\/td><\/td>C36<\/td><\/tr>
SV4
25th July<\/td>		Tim Jansen<\/td>An atom in Jellium<\/td>C36<\/td><\/tr>
SV9
29th August<\/td>		Dr. Nakano<\/td>QMC and the “TurboRVB” code
Abstract below<\/td>		C36<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Talks for next term: Alessandro Romito, Gabriel Bean, Marcin Szyniszewski<\/p>\n\n\n\n

Abstracts<\/h2>\n\n\n\n

Dr. Nakano – QMC and the “TurboRVB” code<\/strong>
First-principles quantum Monte Carlo (QMC) techniques, such as variational quantum Monte Carlo (VMC) and diffusion quantum Monte Carlo (DMC), are among the state-of-the-art numerical methods used to obtain highly accurate many-body wave functions. These methods are especially useful when tackling challenging cases such as low-dimensional materials[1] because QMC is no longer dependent on any semi-empirical exchange-correlation functions. We have been intensively improving a QMC code “TurboRVB,” which has been mainly developed by Prof. Sandro Sorella (SISSA)[2]. I am going to talk about two recent improvements in the QMC algorithm.
The first topic is about all-electron calculations. Although it is convenient to replace core electrons in QMC calculations as in DFT, such replacement sometimes induces nontrivial biases. All-electron calculations in QMC are not as widely used as in DFT because the computational cost scales with Z^5.5\u22126.5, where Z is the atomic number. We have recently developed new algorithms to drastically decrease computational costs of all-electron DFT (valid only for QMC)[3], and all-electron lattice regularized diffusion monte Carlo (LRDMC)[4,5]. I will present basic ideas of the new algorithms and show several applications such as a binding energy calculation of the sodium dimer[3].
The second topic is about a workflow system for QMC optimizations. We are currently developing a python wrapper for TurboRVB, which is called Genius-TurboRVB (g-turbo), in order to “automatize” the complicated optimization procedure of a many-body wave function. The wrapper also makes it much easier to prepare input files, to analyze output files, and to perform advanced calculations. I will present fundamental features and several applications of the wrapper, for example, a phonon dispersion calculation of a solid[6].
[1] S. Sorella, et al. Phys. Rev. Lett. 121, 066402 (2018).
[2] S. Sorella, https:\/\/people.sissa.it\/~sorella\/web\/, accessed 4 August (2019).
[3] K. Nakano, et al. J. Chem. Theory Comput. 15, 4044-4055 (2019).
[4] M. Casula, et al. Phys. Rev. Lett. 95, 100201 (2005).
[5] K. Nakano, et al. to be submitted to Phys. Rev. Lett.
[6] K. Nakano, et al. in preparation.<\/p>\n","protected":false},"excerpt":{"rendered":"

Condensed Matter Theory Group Meetings: Summer 18\/19 This term’s meetings will take place at 11am on Thursdays. Please volunteer a talk or make known any masters students who are willing to give talks. Dice Seminars:Sometimes we run Dice Seminars, which occur over the course of 5 weeks or so, and consist of us collaboratively learning about…<\/p>\n","protected":false},"author":1243,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-53","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/wp.lancs.ac.uk\/condmat\/wp-json\/wp\/v2\/pages\/53","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wp.lancs.ac.uk\/condmat\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/wp.lancs.ac.uk\/condmat\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/wp.lancs.ac.uk\/condmat\/wp-json\/wp\/v2\/users\/1243"}],"replies":[{"embeddable":true,"href":"https:\/\/wp.lancs.ac.uk\/condmat\/wp-json\/wp\/v2\/comments?post=53"}],"version-history":[{"count":3,"href":"https:\/\/wp.lancs.ac.uk\/condmat\/wp-json\/wp\/v2\/pages\/53\/revisions"}],"predecessor-version":[{"id":117,"href":"https:\/\/wp.lancs.ac.uk\/condmat\/wp-json\/wp\/v2\/pages\/53\/revisions\/117"}],"wp:attachment":[{"href":"https:\/\/wp.lancs.ac.uk\/condmat\/wp-json\/wp\/v2\/media?parent=53"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}