Welcome!
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 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".
Other Meetings:
There are ~weekly condensed matter seminars at 3pm on Fridays, which will be interesting for anyone attending our group meetings. These are advertised internally.
Mailing List:
If you would like to be added to the mailing list for these meetings, please subscribe or contact Ryan or Marcin (addresses at page footer).
Dice Seminars:
Sometimes we run Dice Seminars, 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".
Other Meetings:
There are ~weekly condensed matter seminars at 3pm on Fridays, which will be interesting for anyone attending our group meetings. These are advertised internally.
Mailing List:
If you would like to be added to the mailing list for these meetings, please subscribe or contact Ryan or Marcin (addresses at page footer).
Week 
Presenter 
Talk 
Venue 
23
9th May 25
23rd May 26
30th May 27
6th June 28
13th June 29
20th June 30
27th June SV4
25th July SV9
29th August 
TBR
(To Be Rolled) Henning Schomerus
Neil Drummond
David Thomas
Marcin
Szyniszewski Ryan Hunt/
Yassmin Asiri Tom Simons
Tim Jansen
Dr. Nakano

Dice seminar  machine learning weeks 911
Adhesion of graphene to hexagonal boron nitride and gold
Defect Formation Energies in Graphene
Entanglement transition from variablestrength weak measurements
An atom in Jellium
QMC and the "TurboRVB" code
Abstract
Firstprinciples quantum Monte Carlo (QMC) techniques, such as variational quantum Monte Carlo (VMC) and diffusion quantum Monte Carlo (DMC), are among the stateoftheart numerical methods used to obtain highly accurate manybody wave functions. These methods are especially useful when tackling challenging cases such as lowdimensional materials[1] because QMC is no longer dependent on any semiempirical exchangecorrelation 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 allelectron calculations. Although it is convenient to replace core electrons in QMC calculations as in DFT, such replacement sometimes induces nontrivial biases. Allelectron calculations in QMC are not as widely used as in DFT because the computational cost scales with Z^5.5−6.5, where Z is the atomic number. We have recently developed new algorithms to drastically decrease computational costs of allelectron DFT (valid only for QMC)[3], and allelectron 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 GeniusTurboRVB (gturbo), in order to "automatize" the complicated optimization procedure of a manybody 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, 40444055 (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. 
C36
C36
C36
C36
C36
A7
C36
C36
C36

Talks for next term: Alessandro Romito, Gabriel Bean, Marcin Szyniszewski
Made by Marcin Szyniszewski
Maintained by David Thomas
Maintained by David Thomas