Humboldt-Universität zu Berlin - Faculty of Mathematics and Natural Sciences - Physics of low-dimensional systems

Physics of low-dimensional systems







Welcome to our group website!


The main topic of our experimental research is the physics of low-dimensional solid-state systems. We focus on investigating 1D-systems (carbon nanotubes, confined carbyne), 2D-structures (graphene, transition-metal dichalcogenides), and their heterostructures by confocal and tip-enhanced Raman spectroscopy. We want to understand the physics that governs the behavior of these materials, achieve active control over their optical properties, and use them to explore advanced concepts like molecular optomechanics.


Follow us in Twitter: @SHeegLab



News & Highlights


  • July 25, 2022: New manuscript entitled Strain control of hybridization between dark and localized excitons in a 2D semiconductor on ArXiv. In this work we controllably strain monolayer WSe2 membranes at cryogenic temperatures to tune the energy alignment between excitonic species. In this way we bring free dark excitons and localized defect-related excitons together to form a hybridized state that dominates the photoluminiscence response of the material and from which single photon emission likely takes place. Fruitful collaboration with the group Kirill Bolotin at Freie Universität Berlin and the group of Florian Libisch at TU Wien.


  • July 14, 2022: Pablo is awarded the Physik-Studienpreis 2022 by the Physikalische Gesellschaft zu Berlin for his master's degree in Physics at FU Berlin. Congratulations!  




  • June 27, 2022: Sebastian gives a talk on "How to build a career in academia" at the Working in Photonics Conference in Berlin.


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  • June 17, 2022: Pablo presents the group and gives the talk "Strain engineering and hybridization of excitons in 2D semiconductors" at the Friday Light Talks in the main lecture hall of the Lise-Meitner-Haus. Afterwards we shared some beers and very interesting discussions with our colleagues.




  • June 3, 2022: We celebrate the joining of Lala and Giorgia to our group and the visit of our collaborator Dr. Roman Wyss to kick-start MetaMem project with a barbecue in front of the Institut. 


  • June 1, 2022: Welcome, Lala and Giorgia! Lala Habibova and Giorga Marcelli join our group as new team members. Lala and Giorga participate in the AdMaLab program by the Innovation Network for Advanced Materials, a Berlin-based incubator program to promote researchers and young startups that aim to find commercial use for new and advanced materials. Within Team MetaMem, Lala and Giorgia aim to use porous Au membranes for SERS based flow-through sensing and to reveal new material properties. They will be mentored by Sebastian and our collaborator Dr. Roman Wyss from Zürich, Switzerland.


  • March 31, 2022: New publication Freestanding and Permeable Nanoporous Gold Membranes for Surface-Enhanced Raman Scattering has been published in ACS Materials & Interfaces. In this joint work between HU Berlin, IBM Research Rüschlikon and the Photonics Lab at ETH Zürich, we use graphene to show that single nanoscale pores in suspended and mechanically stable porous gold membranes support plasmon-enhanced Raman scattering with enhancements of the order 10^5 at high excitation powers.




  • March 18, 2022: We are happy to announce that we received funding by the Akademischer Senat der Humboldt Universität Berlin within an initiative to foster digital media in research and teaching. We will integrate modern optical experiments located in our labs into teaching by performing them live per remote control from the lecture hall – exciting!


  • December 8, 2021: We are happy to announce that the PLD group joins IRIS Adlershof as a Junior Member.



  • October 27, 2021: The PLD group takes part in an open seminar about Milestones of Quantum technology with participants from around the world where we discuss important papers for Quantum Technology. Get in touch by email if you want join, Wednesdays 16.15 to 17.45.


  • October 5, 2021: Sebastian gives a talk at the Integrative Reseach Institute for Science (IRIS) of Berlin on Exploring Confined Carbyne.



  • October 3, 2021: Welcome to Berlin, Gétulio! Gétulio Silva e Souza Júnior from the Universidade Federal do Rio de Janeiro in Brazil joins our group as a project student.


  • October 1, 2021: Welcome Johannes! Johannes Lechner from the Ludwig-Maximilians-Universität Munich joins our group as a PhD student.





  • May 1, 2021: Welcome Pablo! Pablo Hernández López from the Freie Universität Berlin joins our group as a PhD student.


  • March 17, 2021: Sebastian takes part in the HU Optics Spring Meeting 2021 with his talk Exploring confined carbyne.


  • March 1, 2021: Our group is born! Dr. Sebastian Heeg joins the Institut für Physik of the Humboldt University as the leader of the Emmy-Noether-Group PLD (Physics of Low Dimensional systems) with the project Carbyne for Optoelectronics and Optomechanics.