Complex Systems - Stefan Kettemann

Associate Professor for Complex Systems
School of Computer Science & Engineering
Constructor University Bremen, gGmbH, Campus Ring 1, 28759 Bremen, Germany
Phone number
+49 421 200-3521
Email Address
Research III, Room 96

"To make  the simple complex is common, to make  the complex simple is creative" Charles Mingus

My current Research Interests include (Quantum) Phase Transitions, Superconductivity, Anderson  and Many Body Localization, Quantum transport, and the stability of  Energy Grids 

University Education

Master of Arts and Science, Washington University, St. Louis, 1990

Ph. D. Max Planck Insititute f. Solid State Research, Stuttgart 1994

Habil., Lecturer of Theoretical Physics, Hamburg University, 2001

Fellowships and Awards

World Class University Associate Professor 2009

Research and Teaching Positions

Post Doc at Weizmann Institute, Rehovot, Israel 1994-1996

Post Doc at MPIPKS Stuttgart/Dresden 1996-1999

Assistant at Hamburg University 1999-2001

Lecturer of theoretical Physics at Hamburg University 2001-2008


Visiting Professor at Sophia University, Tokyo and  at Boston University, Boston  2005

University Lecturer of Physics at Jacobs University, since 2008

Associate Professor at POSTECH, since 2009

Research Professor at Jacobs University 2013-2018

Associate Professor of Complex Systems at Jacobs University since 2018

Funded Projects

Recently Funded:

DFG Project Thermodynamics and Dynamics of Long Range Coupled Disordered Quantum Spin Chains
BMBF Project CoNDyNet and CoNDyNet2(Collective Nonlinear Dynamics of Complex Electricity Grids) in collaboration with Potsdam-Institut fur Klimafolgenforschung (PIK), Max-Planck-Institut fur Dynamik und Selbstorganisation (MPIDS),
Frankfurt Institute for Advanced Studies (FIAS), 
Forschungszentrum Julich (FZJ)
DFG Collaboration Project Long Range  Quantum Glasses
DFG-Collaboration Project  Tuning Superconductivity in Doped Semiconductors
DFG-Project Spin-Dynamics and Electron Transport in Structures of Reduced Dimensionality KE 807/6-1  3/4 BAR IIA 1 year
  WCU ( World Class University ) program through  the Korea Science and Engineering Foundation funded by the Ministry of Education, Science and Technology (Pro ject No. R31-2008-000-10059-0) for 5 years, on emergent materials science


Recent Publications

For all Publications see

Quantum Phase Transitions and Quantum Dynamics

Y. Mohdeb, J. Vahedi, S. Haas, R. N. Bhatt, S. Kettemann, Global Quench Dynamics and the Growth  of Entanglement Entropy in Disordered Spin Chains with Tunable Range Interactions,  Phys. Rev. B Letters 108, L140203 (2023).

S. Kettemann, Towards a Comprehensive Theory of Metal-Insulator Transitions in Doped Semiconductors, published in Special Issue in memory of K. B. Efetov, Ann. Phys. (2023).

J. Vahedi, S. Kettemann, Quantum Fidelity of the Aubry-Andre Model and the Exponential Orthogonality Catastrophe, Phys. Rev. B 106, 174204 (2022).

Y. Mohdeb, J. Vahedi, S. Kettemann, Excited-Eigenstate Entanglement Properties of XX Spin Chains with Random Long-Range Interactions, Phys. Rev. B 106, 104201 (2022).

Y. Mohdeb, J. Vahedi, N. Moure, A. Roshani, H.Y. Lee, R. N. Bhatt, S. Haas, S. Kettemann, Entanglement Properties of Disordered Quantum Spin Chains with Long-Range Antiferromagnetic Interactions, Phys. Rev. B 102, 214201 (2020).

D. Aryal, S. Kettemann, Complete Solution of the Tight Binding Model on a Cayley Tree: strongly localised versus extended states , J. Phys. Commun. 4, 105010 (2020).

K. Slevin, S. Kettemann, T. Ohtsuki, Multifractality and the distribution of the Kondo temperature at the Anderson transition, Eur. Phys. J. B 92, 281(2019).


Haicheng Lin, Wantong Huang, Gautam Rai, Yuguo Yin, Lianyi He, Qi-Kun Xue, Stephan Haas, Stefan Kettemann, Xi Chen, and Shuai-Hua Ji, Real-space BCS-BEC crossover in FeSe monolayers , Phys. Rev. B 107, 104517 (2023).

A. Niroula, G. Rai, S. Haas, S. Kettemann, Spatial BCS-BEC Crossover in Superconducting pn-Junctions, Phys. Rev. B 101, 094514 (2020).

Stability of Energy Grids, Dynamics on  Networks
Philipp C. Böttcher, Benjamin Schäfer, Stefan Kettemann, Carsten Agert and Dirk Witthaut,  Local versus global stability in dynamical systems with consecutive Hopf-Bifurcations,  Phys. Rev. Research,  5, 033139 (2023).
Kosisochukwu Pal Nnoli, Fahrudin Delic, Stefan Kettemann, Transient Dynamics and Propagation of Voltage and Frequency Fluctuations in Transmission Grids, IEEE Access 11, 11307 (2023).
Dirk Witthaut, Frank Hellmann, Jürgen Kurths, Stefan Kettemann, Hildegard Meyer-Ortmanns, Marc Timme, Collective Nonlinear Dynamics and Self-Organization in Decentralized Power Grids, Reviews of Modern Physics 94, 015005 (2022).
L. A. Torres-Sanchez, G. T. Freitas de Abreu, S. Kettemann, Analysis of the Dynamics and Topology Dependencies of Small Perturbations in Electric Transmission Grids, Phys. Rev. E 101, 012313 (2020).
Philipp C. Böttcher, Andreas Otto, Stefan Kettemann, Carsten Agert, Time delay effects in the control of synchronous electricity grids, CHAOS 30, 013122 (2020).
H. Haehne, K. Schmietendorf, S. Tamrakar, J. Peinke, S. Kettemann, Propagation of wind power induced fluctuations in power grids, Phys. Rev. E Rapid Communications 99, 050301 (2019).
S. R. Tamrakar, M. Conrath, S. Kettemann, Propagation of Disturbances in AC Electricity Grids, Scientific Reports 8, 6459 (2018).

 Recent Lecture Courses:
 Advanced Quantum Physics
 Advanced Solid State Physics
 Condensed Matter Field Theory
 Renewable Energy
 Applied Ordinary Differential Equations
 Network Theory
 Principles of Statistical Modeling

Other Professional Activities

Study Program Chair of Data Engineering Graduate Program at Constructor University

Scientific (Co-)Organizer of  
International Conference Localisation 2020,  Localisation Seminar Series, Localisation 2022 in Sapporo, Japan

Mathematical and Theoretical Physics Seminar (since 2021)


Referee for  Journals such as  Phys. Rev. Lett., Phys. Rev. B, Phys. Rev. E, Phys. Rev. X,  IEEE ACCESS, Europhys. Lett., Solar Energy,  Applied Physics Lett., Phys. Rev. Applied Letters, IEEE Transaction of Power Systems, Nature Communications,  Europhys. J. B,  European  Physics  Journal, Physica E, Physica Status Solidi,  Annals of Physics, Ann. d. Physik

Funding Agencies such as
          NSF,  DFG, GIF, Humboldt Foundation, EU-Marie-Curie Program

and Faculty promotion referee at US universities


Group Members


Prof. Dr. Isa Zharekeshev,  Al-Farabi Kazakh national university, Almaty, Kazakhstan, Research Area: Anderson Localization, visit 21.11.-20.12.2023

Prof. Dr. Keith Slevin, Department of Physics, Graduate School of Science, Osaka University, Research Area: Anderson Localization,  Visit 11.9.-1.10. 2023

Prof. Dr. Stephan Haas, University of Southern California, Los Angeles, USA, Research Area: Superconductivity, Quantum Magnetism

PhD Students

 M.Sc. Nnoli Kosisochukwu  Pal,  Modelling of Power Grids

Master Students

Bachelor Students

Former Group Members and Visitors

Dr Vincent Sacksteder, Royal Holloway, University of London, Rutgers University

Prof. Dr. Ki-Seok Kim Professor of Theoretical Physics Postech Pohang South Korea DFG Collaboration Program  and DAAD-NRF Scholarship Research Area: Magnetism, Strong Correlations, Superconductivity

Dr. habil. Georges Bouzerar Directeur de Recherche CNRS, Grenoble, France

Prof. Dr. Eduardo Mucciolo, University of Central Florida, Orlando, USA

Dr. Javad Vahedi,  currently   group member of  Synthetic Quantum Systems group of Dr. habil  Martin Gärttner, Heildelberg Univ.

Dr. Michael Conrath, Energy Consultant

Dr. Martin Rohden, Post Doc at USC Davis, USA, Wissenschaftlicher Berater bei VDI/VDE Innovation + Technik GmbH

Dr. Akash Chakraborty, Associate Editor Springer  Nature

Dr. Marcel Kossow, Consultant

Prof. Dr. Kelly Patton, Assistant Prof. of Physics and Astronomy at Georgia Southern University, USA

Dr Youcef Mohdeb  PhD 2022 JUB with distinction Thermodynamics and Dynamics of  Random Spin Chains with Long Range Interactions, Quantum Engineer at ColibrITD,  Paris

Dr Daniel Jung PhD 2014  JUB  Impact of Local Magnetic Moments on the Anderson Metal-Insulator Transition  Research Fellow, European Commission, Joint Research Centre (EC-JRC), Petten, Netherlands

Prof. Dr Hyun Yong Lee PhD 2014 Postech Magnetic Properties of Disordered Electron Systems   Prof. in Computational Many Body Physics, Korea University

Dr Aleksander Hinz PhD 2013, Hamburg University Thermoelectric Properties of Graphene

Dr habil. Paul Wenk, PhD 2011, Hamburg University,  Itinerant Spin-Dynamics in Structures of Reduced Dimensionality,  Permanent  Academic Member AG Heuer, Univ. Münster

Dr Björn Vogt, PhD 2009, Hamburg University,  Reduction of Quantum Fluctuations by Anisotropy Fields in Heisenberg Ferro- and Antiferromagnets, Klett-Verlag, Stuttgart, Germany

Prof. Dr Riccardo Mazzarello PhD 2004 Hamburg University   Prof.,  professore associato, Sapienza Università di Roma.


Thang Trinh: Energy price prediction for German market Using Machine learning and Deep Learning techniques


Berk Dikici: Electricity Price Forecasting using Autonomous Streaming Pipeline

Eno Ciraku: Analysis and Forecast of Frequency in Electrical Grids


Rohan Kumar:  Stochastic Modelling and Forecasting of EPEX SPOT Prices using VAR and VEC Models

Didier Iyamuremye: Forecasting Day-Ahead Energy Prices

Nikitha Adidela: Comparison of Time series forecasting models on Austrian Energy market


Narendrakumar Hosamani: Analysis and Forecast of Control Power Demand in the German Power Grid

Any-Arlene Niyubahwe: Forecast of Phasor information in Grid- Connected Photovoltaics

B. Sc. Clara Elisabeth Buller,  BSc Thesis (2023) Optimizing energy dispatch utilizing uncertainty information in probabilistic forecasts

B. Sc. Fahrudin Delić, BSc Thesis (2022) Numerical Analysis of Transient Dynamics and Propagation of Voltage Fluctuations in Power Transmission Grids

B.Sc. Justinas Zaliaduonis, BSc Thesis (2022) Forecasting of Power Grid Dynamics with Reservoir Computing

B. Sc. Sivanessha Kalithasan, BSc Thesis (2021) Jordan Wigner Transformation and Strong Disorder Renormalisation Group (SDRG) for disordered spins on a Cayley Tree


B. Sc Yu-Chih Liang BSc Thesis (2019) Analysis on the weighted Laplacian matrix of inhomogeneous power grids network, Physics Teacher in Taiwan

M Sc. Kiran Adikhari, BSc Theis (2018)  Effect of External Fields on Majorana Zero Modes, PhD Student TU Munuch

MSc. Alexander Mchedlishvili, BSc Thesis (2018)  The Effects of Wind Turbine Short-Term Power Fluctuations on the German Power Grid, PhD Student University of Bremen, Institute of Environmental Physics

M.Sc. Avinash Niroula, BSc. Thesis (2017) Superconductor-Insulator Transition in Doped Semiconductors, Data Engineer Raisin Bank AG 

M. Sc.  Luiscarlos Torres Sanchez BSc Thesis (2016): Close-to-Steady-State Dynamics of Phase Perturbations in Transmission Grids. Energy Market Consultant KYOS

B. Sc. Sven Wasmus Bachelor Thesis (2016): Concurrence in Disordered Quantum Spin Chains

M. Sc. Samyak Tamrakar BSc Thesis (2015): Cascading Failure in Power Grids using Dynamic AC Flow Model, Data Engineer

M. Sc. Vincent Steininger BSc Thesis (2015): Thermoelectrics of p-n Junctions, PhD student, Hemlut Schmidt University Hamburg

M. Sc. Bogomil Paralchev, Bachelor Thesis (2014): Statistical Analysis and Modelling of Power Failures, Data Scientist

Dr Manish Jung Thapa Bachelor Thesis (2014): Entanglement of Electron Spins in the Fermi Sea, Quantum Engineer, IQM Quantum Computers

B.Sc. Emmanuel Chigwedere, Bachelor Thesis (2013) Optimization of Thin-Film Thermoelectric Generators