ERC FUNDED PROJECTS

Quantum optics, the study of how discrete packets of light (photons) and matter interact, has led to the development of remarkable new technologies which exploit the bizarre properties of quantum mechanics. These quantum technologies are primed to revolutionize the fields of communication, information processing, and metrology in the coming years. Similar to contemporary technologies, the future quantum machinery will likely consist of a semiconductor platform to create and process the quantum information. However, to date the demanding requirements on a quantum photonic platform have yet to be satisfied with conventional bulk (three-dimensional) semiconductors. To surmount these well-known obstacles, a new paradigm in quantum photonics is required. Initiated by the recent discovery of single photon emitters in atomically flat (two-dimensional) semiconducting materials, 2DQP aims to be at the nucleus of a new approach by realizing quantum optics with ultra-stable (coherent) quantum states integrated into devices with electronic and photonic functionality. We will characterize, identify, engineer, and coherently manipulate localized quantum states in this two-dimensional quantum photonic platform. A vital component of 2DQP’s vision is to go beyond the fundamental science and achieve the ideal solid-state single photon device yielding perfect extraction - 100% efficiency - of on-demand indistinguishable single photons. Finally, we will exploit this ideal device to implement the critical building block for a photonic quantum computer.

1 999 135 €

Start date: 2018-01-01, End date: 2022-12-31

Large protein complexes carry out some of the most complex functions in biology. Such structures are often assembled spontaneously from individual components through the process of self-assembly. If self-assembled protein complexes could be engineered from first principle it would enable a wide range of applications in biomedicine, nanotechnology and materials science. Recently, approaches to rationally design proteins to self-assembly into predefined structures have emerged. The highlight of this work is the design of protein cages that may be engineered into protein containers. However, current approaches for self-assembly design does not result in the assemblies with the required structural complexity to encode many of the sophisticated functions found in nature. To move forward, we have to learn how to engineer protein subunits with more than one designed interface that can assemble into tightly interacting complexes. In this proposal we propose a new protein design paradigm, shape directed protein design, in order to address shortcomings of the current methodology. The proposed method combines geometric shape matching and computational protein design. Using this approach we will de novo design assemblies with a wide variety of structural states, including protein complexes with cyclic and dihedral symmetry as well as icosahedral protein capsids built from novel protein building blocks. To enable these two design challenges we also develop a high-throughput assay to measure assembly stability in vivo that builds on a three-color fluorescent assay. This method will not only facilitate the screening of orders of magnitude more design constructs, but also enable the application of directed evolution to experimentally improve stable and assembly properties of designed containers as well as other designed assemblies.

2 325 292 €

Start date: 2018-06-01, End date: 2023-05-31

One of the greatest challenges in exploiting the electron spin for information processing is that it is not a conserved quantity like the electron charge. In addition, spin lifetimes are rather short and correspondingly coherence is quickly lost. This challenge culminates in the coherent manipulation and detection of information from a single spin. Except in a few special systems, so far, single spins cannot be manipulated coherently on the atomic scale, while spin coherence times can only be measured on spin ensembles. A new concept is needed for coherence measurements on arbitrary single spins. Here, the principal investigator (PI) will combine a novel time- and spin-resolved low-temperature scanning tunneling microscope (STM) with the concept of pulsed electron paramagnetic resonance. With this unique and innovative setup, he will be able to address long-standing problems, such as relaxation and coherence times of arbitrary single spin systems on the atomic scale as well as individual spin interactions with the immediate surroundings. Spin readout will be realized through the detection of the absolute spin polarization in the tunneling current by a superconducting tip based on the Meservey-Tedrow-Fulde effect, which the PI has recently demonstrated for the first time in STM. For the coherent excitation, a specially designed pulsed GHz light source will be implemented. The goal is to better understand the spin dynamics and coherence times of single spin systems as well as the spin interactions involved in the decay mechanisms. This will have direct impact on the feasibility of quantum spin information processing with single spin systems on different decoupling surfaces and their scalability at the atomic level. A successful demonstration will enhance the detection limit of spins by several orders of magnitude and fill important missing links in the understanding of spin dynamics and quantum computing with single spins.

2 469 136 €

Start date: 2016-07-01, End date: 2021-06-30

Replacement of petrochemistry by bio-based processes is key to sustainable development and requires microbes equipped with novel-to-nature capabilities. The efficiency of such engineered microbes strongly depends on their native metabolic networks. However, aeons of evolution have optimized these networks for fitness in nature rather than for industrial performance. As a result, central metabolic networks are complex and encoded by mosaic microbial genomes in which genes, irrespective of their function, are scattered over the genome and chromosomes. This absence of a modular organization tremendously restricts genetic accessibility and presents a major hurdle for fundamental understanding and rational engineering of central metabolism. To conquer this limitation, I introduce the concept of ‘pathway swapping’, which will enable experimenters to remodel the core machinery of microbes at will. Using the yeast Saccharomyces cerevisiae, an industrial biotechnology work horse and model eukaryotic cell, I propose to design and construct a microbial chassis in which all genes encoding enzymes in central carbon metabolism are relocated to a specialized synthetic chromosome, from which they can be easily swapped by any – homologous or heterologous – synthetic pathway. This challenging and innovative project paves the way for a modular approach to engineering of central metabolism. Beyond providing a ground-breaking enabling technology, the ultimate goal of the pathway swapping technology is to address hitherto unanswered fundamental questions. Access to a sheer endless variety of configurations of central metabolism offers unique, new possibilities to study the fundamental design of metabolic pathways, the constraints that have shaped them and unifying principles for their structure and regulation. Moreover, this technology enables fast, combinatorial optimization studies on central metabolism to optimize its performance in biotechnological purposes.

2 149 718 €

Start date: 2015-09-01, End date: 2020-08-31