Dr. Procopios Christou Constantinou

Procopios Constantinou

Project Scientist

Paul Scherrer Institut
Forschungsstrasse 111
5232 Villigen PSI

Procopios Constantinou currently holds the position of Project Scientist in the Laboratory for Advanced Spectroscopy and X-ray Sources (LSX) in the Spectroscopy of Quantum Materials Group, working under the guidance of Dr. Vladimir Strocov. He earned his PhD from University College London (UCL), UK, and his MPhys with first-class honors from Cardiff University, UK.

During his time at Cardiff University, he focused on modeling the convergent beam low-energy electron diffraction (CBLEED) patterns of various reconstructed silicon variants. During his time at UCL, he was part of the London Center for Nanotechnology, specifically within the Center for Doctoral Training for the Advanced Characterization of Materials (CDT-ACM). His primary role involved the fabrication and characterization of metallic, two-dimensional dopant δ-layers in silicon using angle-resolved photoemission spectroscopy (ARPES) and scanning tunneling microscopy (STM). Upon the completion of his PhD, he took on a postdoctoral role at PSI where he led a collaboration with an industry partner to perform beamtime experiments (ARPES, XPS, STM) on superconductor–semiconductor hybrid heterostructures and many other quantum materials.

Procopios currently serves as the technical lead for one of PSI’s industry collaborations. His responsibilities encompass the planning, organization, preparation and execution of beamtimes, both at the SLS and at external facilities. The primary focus of these experiments is photoelectron spectroscopy (ARPES, XPS, HAXPES) and STM. Furthermore, Procopios is actively involved in the development of software for the theoretical modelling of depth profile photoelectron spectroscopy data. This software aids in the accurate reconstruction of layered heterostructures by fitting layer thicknesses. He also spearheads a team tasked with relocating the SX-ARPES end-station from the SLS to PETRA-III in Hamburg, Germany. This involves the complete disassembly of the laboratory, packaging, transportation, and reassembly at PETRA-III. Once the SX-ARPES end-station is operational in Hamburg, he will provide user support to users and conduct his own in-house scientific research.

Procopios specializes in conducting experimental spectroscopic studies on innovative quantum materials using soft x-rays. His research, which lies at the intersection of nanotechnology and photon science, has significant implications for quantum information processing and silicon quantum electronics. His work contributes to the advancement of these fields and opens up new possibilities for technological applications. He has also delved into the fundamental electronic structure properties of a diverse range of solid-state quantum systems, spanning from single crystals to complex buried heterostructures and impurity systems, which are the building blocks of current and future electronic devices.

A full publication list can be accessed online through this link .

EUV-induced hydrogen desorption as a step towards large-scale silicon quantum device patterning.
P. Constantinou, T. J. Z. Stock, L.T. Tseng, D. Kazazis, M. Muntwiler, C. A. F. Vaz, Y. Ekinci, G. Aeppli, N. J. Curson, S. R. Schofield
Nature Communications, 15, 694 (2024)


Momentum-Space Imaging of Ultra-Thin Electron Liquids in δ-Doped Silicon
P. Constantinou, T. J. Z. Stock, E. Crane, A. Kölker, M. Loon, J. Li, S. Fearn, H. Bornemann, N. D'Anna, A. J. Fisher, V. N. Strocov, G. Aeppli, N. J. Curson, S. R. Schofield
Advanced Science, 10, 2302101 (2023)


High-energy photoemission final states beyond the free-electron approximation
V. N. Strocov, L. L. Lev, F. Alarab, P. Constantinou, X. Wang, T. Schmitt, T. J. Z. Stock, L. Nicolaï, J. Očenášek, J. Minár
Nature Communications, 14, 4827 (2023)


Atomic-Scale Patterning of Arsenic in Silicon by Scanning Tunneling Microscopy.
T. J. Z. Stock, O. Warschkow, P. C. Constantinou, J. Li, S. Fearn, E. Crane, E. V. S. Hofmann, A. Koelker, D. R. McKenzie, S. R. Schofield, N. J. Curson
ACS Nano, 14 (3), 3316 – 3327 (2020).


On the sensitivity of convergent beam low energy electron diffraction patterns to small atomic displacements.
P. C. Constantinou & D. E. Jesson.
Applied Surface Science, 489, 504–509 (2019).