09.12.2018

High level research at the nanoscale

The Nanoscience Center (NSC) hosts more than hundred researchers with a background in biology, chemistry or physics. The strength of NSC is that there are people from all areas, from practical biologists to theoretical physicists. In addition to experimental work, substantial effort is invested in the theoretical and computational study of nanosystems.

2018

Modeling catalytic water-gas-shift at the metal-oxide interfaceTRY.png

The industrially important water–gas shift (WGS) reaction is a complex network of competing elementary reactions, where the catalyst is a multicomponent system consisting of distinct domains. In particular, the interface between the metal and oxide has gained interest as the main active site. Researchers at University of Jyväskylä have combined density functional theory calculations with microkinetic modeling to explore the active phase, kinetics, and reaction mechanism of the WGS over Rh/ZrO2. The work highlights the general challenges in microkinetic modeling and the findings demonstrate the central role of the interface in the water–gas shift reaction, and the importance of modeling both the support and the metal in bifunctional systems. The research was recently published in American Chemical Society Catalysis.

M.M.Kauppinen, M.M. Melander, A.S. Bazhenov, and K. Honkala, "Unraveling the Role of the Rh-ZrO2 Interface in the Water-Gas-Shift Reaction via a First-Principles Microkinetic Study", ACS Catal. (8), (2018)

 

How to melt gold at room temperature?186467_web.jpg

As tension rises unexpected things can happen. This is also true for gold atoms. Researchers, have, for the first time, managed to make the surface of a gold object melt at room temperature. The discovery of how gold atoms can lose their structure in this way is not just spectacular, but also groundbreaking scientifically. Ludvig de Knoop, together with the theoretician Mikael Juhani Kuisma and coworkers, have opened up new avenues in materials science. The results are now published in the journal Physical Review Materials.

L. de Knoop, M. J. Kuisma, J. Löfgren, K. Lodewijks, M. Thuvander, P. Erhart, A. Dmitriev, and E. Olsson, "Electric-field-controlled reversible order-disorder switching of a metal tip surface", Phys. Rev. Materials 2, 085006 (2018), JYX publication, and JYU press release.

 

Electron transport in superconductor/ferromagnet materials reviewed

According to a commonly held view, all metals become either superconducting or magnetic at low enough temperatures. What is harder is to find a material with a simultaneous combination of both effects. Nanotechnology makes it possible as thin film superconductors next to ferromagnetic insulators inherit magnetic properties from the latter. The simultaneous presence of the two effects bring in unexpected effects such as a giant thermoelectric effect or long-range spin signals. NSC researchers together with their colleagues from Italy and Spain have now provided the first comprehensive review of nonequilibrium effects in such heterostructures. This review was published in Reviews of Modern Physics.

F. S. Bergeret, M. Silaev, P. Virtanen, and T. T. Heikkilä, "Colloquium: Nonequilibrium effects in superconductors with a spin-splitting field", Rev. Mod. Phys. 90, 041001 (2018), and JYX publication.

 

Molecular memory can be used to increase the memory capacity of hard disksyksittäismolekyylimagneetti-Mansikkamäki.jpg

Researchers at the University of Jyväskylä have taken part in an international British-Finnish-Chinese collaboration where the first molecule capable of remembering the direction of a magnetic above liquid nitrogen temperatures has been prepared and characterized. The results may be used in the future to massively increase the storage capacity of hard disks without increasing their physical size. The research was published in Science

F.-S. Guo, B. M. Day, Y.-C. Chen, M.-L. Tong, A. Mansikkamäki, and R. A. Layfield. "Magnetic hysteresis up to 80 K in a dysprosium metallocene single-molecule magnetScience, (2018), and JYU press release.

DNA-nanoparticle actuator enabling optical monitoring of nanoscale movements induced by electric field

Highlight_Toppari.jpgOver the past decades, nanoactuators for detection or probing of different biomolecules have attracted vast interest for example in the fields of biomedical, food and environmental industry. To provide more versatile tools for active molecular control in nanometer scale, researchers from the NSC in the University of Jyväskylä, University of Tampere, and BioNavis Ltd have devised a nanoactuator scheme, where gold nanoparticle (AuNP) tethered on a conducting surface is moved reversibly using electric fields, while monitoring its position optically via changes of its plasmon resonance. Forces induced by the AuNP motion on the molecule anchoring the nanoparticle, can be used to change and study its conformation. The research was published in Nanoscale.

K. Tapio, D. Shaoa, S. Auer, J. Tuppurainen, M. Ahlskog, V. P. Hytönen, and J. J. Toppari, "DNA-nanoparticle actuator enabling optical monitoring of nanoscale movements induced by electric field", Nanoscale 10, 19297 (2018), and JYU press release.

Magic shells of electrons and atoms seen in nanoparticle synthesis for the first time

hannu.pngA collaboration between cluster chemists in Xiamen University and computational nanoscientists in the NSC has revealed a new breakthrough in understanding of formation of nanometer-sized noble metal nanoparticles in chemical synthesis. The mechanisms that affect nucleation and growth in chemical synthesis of metal nanoparticles have been debated for decades. Now, for the first time, both these stabilization mechanisms are directly seen in the same synthesis of nanoparticles that are made of gold and silver atoms. The work was published in Nature Communications.

J. Yan, S. Malola, C. Hu, J. Peng, B. Dittrich, B.K. Teo, H. Häkkinen, L. Zheng, and N. Zheng, "Co-crystallization of atomically precise metal nanoparticles driven by magic atomic and electronic shells", Nature Comm (2018), and JYX publication.

New information to understand regulation of muscle function in muscle dystrophy patients

ylanne-electronmicroscope.pngIn multicellular organism cell adhesion to other cells and to the extracellular matrix is very tightly regulated. Depending on the tissue, the attachment structures are adjusted to tolerate various pulling forces and sometimes the attachments are opened and reorganized. For force tolerance adhesion proteins in the cellular membrane need to be connected to intracellular structural elements, the cytoskeleton, and this connection is the key regulatory point. The research groups from Department of Biological and Environmental Science at the University of Jyväskylä and from Department of Physiology, Development and Neuroscience at the University of Cambridge have studies for several years so called mechanosensor proteins, whose function change according to pulling force. The research is important for the basic understanding of regulation of muscle function for instance in muscle dystrophy patients and muscle adaptation to physical activity and sports. The research was published in eLife.

H. J. Green, A. G. M. Griffiths, J. Ylänne, and N. H. Brown, "Novel functions for integrin-associated proteins revealed by analysis of myofibril attachment in Drosophila", eLife 7, e35783 (2018) and JYU press release.

Real-space imaging with pattern recognition of a ligand-protected Ag374 nanocluster at sub-molecular resolution

Highlight_Hakkinen.jpegHigh-resolution imaging of nanoparticlesurface structures is now possible. Using scanning tunnelling microscopy (STM), extremely high resolution imaging of the molecule-covered surface structures of silver nanoparticles is possible, even down to the recognition of individual parts of the molecules protecting the surface. This was the finding of joint research between China and Finland, led in Finland by Academy Professor Hannu Häkkinen of the University of Jyväskylä. The research was recently published in the prestigious Nature Communications series and the publication was selected by the journal editors to the journal’s monthly collection of highlighted papers.

Q. Zhou, S. Kaappa, S. Malola, H. Lu, D. Guan, Y. Li, H. Wang, Z. Xie, Z. Ma, H. Häkkinen, N. Zheng. X. Yang, and L. Zheng, "Real-space imaging with pattern recognition of a ligand-protected Ag374 nanocluster at sub-molecular resolution" Nature Comm 9, 2948 (2018), JYX publication, JYU press release, and AKA press release.

A game-change in aluminium chemistry

Link to complex.jpgA collaborative research effort between the Departments of Chemistry at the University of Oxford (United Kingdom) and University of Jyväskylä (Finland) has resulted in the discovery of a completely new mode of reactivity for compounds of aluminium – one of the most technologically important elements of the Periodic Table. This new capability may find further use in applications involving the formation of new metal-carbon and metal-metal bonds. The research was published in Nature.

J. Hicks, P. Vasko, J. M. Goicoechea, and S. Aldridge, "Synthesis, structure and reaction chemistry of a nucleophilic aluminyl anion", Nature 557, 92 (2018), JYX publication, and JYU press release.

Stabilized entanglement of massive mechanical oscillators

Highlight_Massel.jpegResearchers at the University of Jyväskylä (Finland) participated in an international collaboration with research groups from Aalto University (Finland), UNSW (Australia) and University of Chicago (United States) and showed that it is possible to create an entangled state for the dynamics of two mechanical objects each constituted by 1012 (1 followed by twelve zeroes) atoms! This allowed them to demonstrate how some of the most counterintuitive predictions of quantum mechanics can be verified in nearly-macroscopic objects. The research was published in Nature.

C. F. Ockeloen-Korppi, E. Damskägg, J. M. Pirkkalainen, M. Asjad, A. A. Clerk, F. Massel, M. J. Woolley, and M. A. Sillanpää, "Stabilized entanglement of massive mechanical oscillators", Nature 556, 478 (2018), and JYU press release.

From symmetry breaking to unraveling the origin of the chirality of ligated Au13Cu2 nanoclusters

Highlight_Hakkinen2.jpegThis collaborative work between NSC (Acad. Prof. Häkkinen) and Xiamen University (Prof. Nanfeng Zheng) demonstrates a new method to synthesize and characterize optically pure ultra-small chiral Au-Cu clusters protected by pyridinethiols and chiral diphosphines. DFT calculations done at the NSC reveal the details of the origin of the chiral optical response of these nanomaterials, which resist racemization up to 70 C making them potentially interesting materials for enantioselective catalysis. The research was published in Angewandte Chemie.

G. Deng, S. Malola, J. Yan, J. Han, P. Yuan, C. Zhao, X. Yuan, S. Lin, Z. Tang, B. K. Teo, H. Häkkinen, N. Zheng, "From Symmetry Breaking to Unraveling the Origin of the Chirality of Ligated Au13Cu2 Nanoclusters" Angew Chem 57, 13, 3421 (2018), JYX publication, and JYU press release.

Extinct type of human parvovirus B19 persists in tonsillar B cells

Vihinen-Ranta-image-nsc.docx.jpg

Research groups from the NSC in the University of Jyväskylä and Department of Virology in the University of Helsinki have reported that Parvovirus B19 (B19V) DNA persists lifelong in human tonsillar tissues. The B19V DNA is most frequent and abundant among B cells, and within them they find a B19V genotype that vanished from circulation 440 years ago. The research was published in Nature Communications.

L. Pyöriä, M. Toppinen, E. Mäntylä, L. Hedman, L.M. Aaltonen, M. Vihinen-Ranta, T. Ilmarinen, M. Söderlund-Venermo, K. Hedman, and M. Perdomo, "Extinct type of human parvovirus B19 persists in tonsillar B cells" Nature Comm 4, 14930 (2018), JYX publication, Nature microbiology community, and JYU press release.

Building miniature optical antennas using DNA as a guide 21519df3-de61-4dfb-9263-402c8bf591a0-2.jpeg

Research groups from the NSC in the University of Jyväskylä and Aalto University (Finland) together with researchers from California Institute of Technology (Caltech, USA) and Aarhus University (iNANO Center, Denmark) have reported a new highly parallel technique to fabricate precise metallic nanostructures with designed plasmonic properties by means of different self-assembled DNA origami shapes. The so-called DALI (DNA-assisted lithography) method has been published in the latest issue of Science Advances.

B. ShenV. LinkoK. TapioS. Pikker, T. LemmaA. GopinathK. V. GothelfM. A. Kostiainen and J. J. Toppari, "Plasmonic nanostructures through DNA-assisted lithographyScience Adv 4, 8978 (2018), JYX publication, JYU press release, and AKA press release.

New research opening for atomically thin metal nanostructures45b64cc2-1239-4ea2-81b9-337b0ca5bc47.png

Researchers at the NSC in the University of Jyväskylä predict systematically the properties of atomically thin structures made exclusively from metallic elements. This provides an atlas for two-dimensional elemental metals. The research was published in Physical Review B.

J. Nevalaita and P. Koskinen, "An Atlas of two-dimensional elemental metals", Phys Rev B 97, 035411 (2018), and JYU press release.

2017

Helium ions reveal how viruses attack bacteria bakteriofaagit.jpg

An interdisciplinary research consortium from the NSC at University of Jyvaskyla in Finland (group leaders Dr. Lotta-Riina Sundberg and Prof. Ilari Maasilta) has found that bacteria and viruses can be imaged with helium ions in contrast to electrons which are the standard workhorse in nanoscale microscopy. Helium ions, being more massive than electrons, can be focused to a much tighter spot down to the atomic length scales. By measuring the electrons generated by the ion bombardment, an image can be formed from the sample with biological features visible below the nanometer (one billionth of a meter) length. The research was published in Advanced Biosystems.

M. Leppänen, L.-R. Sundberg, E. Laanto, G. Magno de Freitas Almeida, P. Papponen, and I. J. Maasilta, "Imaging Bacterial Colonies and Phage–Bacterium Interaction at Sub-Nanometer Resolution Using Helium-Ion Microscopy", Adv Biosys 1, 1700070 (2017)

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Quantum theory for manipulating nanomagnets 

Researchers at the Department of Physics, Universityof Jyväskylä, Finland, have created a theory that predicts the properties of nanomagnets manipulated with electric currents. This theory is useful for future quantum technologies. The research was published in Physical Review Letters.

P. Virtanen and T. T. Heikkilä,Spin Pumping and Torque Statistics in the Quantum Noise LimitPhy Rev Lett 118, 237701 (2017)

Researchers beat the quantum limit of microwave measurements rumpuwiggle.jpg

Research groups at Aalto University and the University of Jyväskylä have demonstrated a new microwav measurement method that goes to the quantum limit of measurement and beats it. The new method can potentially be used for example in quantum computing and measurement of gravitational waves. The research was published in Physical Review Letters.

C. F. Ockeloen-Korppi, E. Damskägg, J.-M. Pirkkalainen, T. T. Heikkilä, F. Massel, and M. A. Sillanpää, "Noiseless Quantum Measurement and Squeezing of Microwave Fields Utilizing Mechanical Vibrations” Phys Rev Lett 118, 103601 (2017)