## Abstract

In condensed-matter physics, strongly-correlated systems refer to materials that exhibit variety of fascinating properties and ordered phases, depending on temperature, doping, and other factors. Such unique properties most notably arise due to strong electron-electron interactions, and in some cases due to interactions involving other quasiparticles as well. Electronic correlation effects are non-trivial that one may need a sufficiently accurate approximation technique with quite heavy computation, such as Quantum Monte-Carlo, in order to capture particular material properties arising from such effects. Meanwhile, less accurate techniques may come with lower numerical cost, but the ability to capture particular properties may highly depend on the choice of approximation. Among the many-body techniques derivable from Feynman diagrams, we aim to formulate algorithmic implementation of the Ladder Diagram approximation to capture the effects of electron-electron interactions. We wish to investigate how these correlation effects influence the temperature-dependent properties of strongly-correlated metals and semiconductors. As we are interested to study the temperature-dependent properties of the system, the Ladder diagram method needs to be applied in Matsubara frequency domain to obtain the self-consistent self-energy. However, at the end we would also need to compute the dynamical properties like density of states (DOS) and optical conductivity that are defined in the real frequency domain. For this purpose, we need to perform the analytic continuation procedure. At the end of this study, we will test the technique by observing the occurrence of metal-insulator transition in strongly-correlated metals, and renormalization of the band gap in strongly-correlated semiconductors.

Original language | English |
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Title of host publication | International Symposium on Current Progress in Mathematics and Sciences 2016, ISCPMS 2016 |

Subtitle of host publication | Proceedings of the 2nd International Symposium on Current Progress in Mathematics and Sciences 2016 |

Editors | Kiki Ariyanti Sugeng, Djoko Triyono, Terry Mart |

Publisher | American Institute of Physics Inc. |

ISBN (Electronic) | 9780735415362 |

DOIs | |

Publication status | Published - 10 Jul 2017 |

Event | 2nd International Symposium on Current Progress in Mathematics and Sciences 2016, ISCPMS 2016 - Depok, Jawa Barat, Indonesia Duration: 1 Nov 2016 → 2 Nov 2016 |

### Publication series

Name | AIP Conference Proceedings |
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Volume | 1862 |

ISSN (Print) | 0094-243X |

ISSN (Electronic) | 1551-7616 |

### Conference

Conference | 2nd International Symposium on Current Progress in Mathematics and Sciences 2016, ISCPMS 2016 |
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Country | Indonesia |

City | Depok, Jawa Barat |

Period | 1/11/16 → 2/11/16 |

## Keywords

- analytic continuation
- ladder diagram
- Matsubara frequency
- strongly-correlated systems
- vertex function