Research Interests : Properties and electronic band structure of topological and 2D materials

Email : s.fragkos@inn.demokritos.gr

Research Interests
Properties and electronic band structure of topological and 2D materials
Position
PhD Students
Telephone
+30 210 650 3338 - 3341
About/Biography


Sotirios Fragkos is a PhD student of University of West Attica since 2019, with dissertation title “On topological properties of materials: Topological insulators, Weyl and Dirac semimetals” in collaboration with the Epitaxy and Surface Science Laboratory (ESSL) within the framework of Horizon 2020 “SKYTOP” project, coordinated by National Centre for Scientific Research “Demokritos”.

He received his BSc degree on Mechanical Engineering in 2017, from the Technological Educational Institute of Piraeus, Greece. For his undergraduate thesis, he studied “On electronic band structure of 2D materials, combining angle-resolved photoemission spectroscopy (ARPES) and density functional theory (DFT)”.

Since 2017, he is a member of the ESSL, headed by Dr Athanasios Dimoulas, of the Institute of Nanoscience and Nanotechnology of NCSR "Demokritos".

His main interests focus on the theoretical study of Topological Insulators, Weyl and Dirac semimetals and 2D Materials by DFT and their experimental characterization by ARPES. He has (co)authored publications in peer-reviewed scientific journals and participated in international scientific conferences.

PUBLICATIONS

1) S. Fragkos, P. Tsipas, E. Xenogiannopoulou, Y. Panayiotatos and A. Dimoulas, Type-III Dirac fermions in HfxZr1−xTe2 topological semimetal candidate, J. Appl. Phys. 129, 075104 (2021)
https://doi.org/10.1063/5.0038799

2) S. Fragkos, L. Baringthon, P. Tsipas, E. Xenogiannopoulou, P. Le Fèvre, P. Kumar, H. Okuno, N. Reyren, A. Lemaitre, G. Patriarche, J.-M. George and A. Dimoulas, Topological surface states in epitaxial (SnBi2Te4)n (Bi2Te3)m natural van der Waals superlattices, Phys. Rev. Materials 5, 014203 (2021).
https://doi.org/10.1103/PhysRevMaterials.5.014203

3) S. Fragkos, R. Sant, C. Alvarez, E. Golias, J. Marquez-Velasco, P. Tsipas, D. Tsoutsou, S. Aminalragia-Giamini, E. Xenogiannopoulou, H. Okuno, G. Renaud, O. Rader and A. Dimoulas, Topological band crossings in epitaxial strained SnTe, Phys. Rev. Materials 3, 104201 (2019).
https://doi.org/10.1103/PhysRevMaterials.3.104201

4) C. Zacharaki, P. Tsipas, S. Chaitoglou, S. Fragkos, M. Axiotis, A. Lagoyiannis, R. Negrea, L. Pintilie and A. Dimoulas, Very large remanent polarization in ferroelectric Hf1-xZrxO2 grown on Ge substrates by plasma assisted atomic oxygen deposition, Appl. Phys. Lett. 114, 112901 (2019).
https://doi.org/10.1063/1.5090036

5) S. Fragkos, R. Sant, C. Alvarez, P. Tsipas, D. Tsoutsou, H. Okuno, G. Renaud, R. Alcotte, T. Baron and A. Dimoulas, Room Temperature Commensurate Charge Density Wave in Epitaxial Strained TiTe2 Multilayer Films, Adv. Mater. Interfaces 6, 1801850 (2019).
https://doi.org/10.1002/admi.201801850

6) P. Tsipas, S. Fragkos, D. Tsoutsou, C. Alvarez, R. Sant, G. Renaud, H. Okuno, and A. Dimoulas, Direct Observation at Room Temperature of the Orthorhombic Weyl Semimetal Phase in Thin Epitaxial MoTe2, Adv. Funct. Mater. 28, 1802084 (2018).
https://doi.org/10.1002/adfm.201802084

7) P. Tsipas, D. Tsoutsou, S. Fragkos, R. Sant, C. Alvarez, H. Okuno, G. Renaud, R. Alcotte, T. Baron, and A. Dimoulas, Massless Dirac Fermions in ZrTe2 Semimetal Grown on InAs (111) by van der Waals Epitaxy, ACS Nano 12, 1696-1703 (2018).
https://doi.org/10.1021/acsnano.7b08350

CONFERENCES

1) S. Fragkos, P. Tsipas, D. Tsoutsou, E. Xenogiannopoulou, R. Sant, C. Alvarez, G. Renaud, H. Okuno, Y. Panayiotatos and A. Dimoulas, Epitaxial HfTe2, ZrTe2 and type-III Dirac fermions in HfxZrx-1Te2 topological semimetal candidate, APS March Meeting, Virtual, 15-19 March 2021. Oral presentation
https://meetings.aps.org/Meeting/MAR21/Event/398517

2) S. Fragkos, P. Tsipas, D. Tsoutsou, R. Sant, C. Alvarez, G. Renaud, H. Okuno, and A. Dimoulas, Epitaxial growth and characterization of topological semimetals from the 2D transition metal dichalcogenides family, APS March Meeting, Denver – Colorado, 2-6 March 2020. Oral presentation
http://meetings.aps.org/Meeting/MAR20/Session/B60.4

3) S. Fragkos, P. Tsipas, D. Tsoutsou, R. Sant, C. Alvarez, G. Renaud, H. Okuno, and A. Dimoulas, Epitaxial growth and characterization of 2D transition metal dichalcogenides topological semimetals, XXXIV Panhellenic Conference on Solid State Physics and Materials Science, Patras, 11-14 September 2019. Oral presentation
http://xxxiv-ssm.upatras.gr/program/