News 2015

Paper Appears in Physical Review B

Our paper entitled, Magnetization reversal of an individual exchange-biased permalloy nanotube, appeared in Physical Review B on the 22nd. The report describes measurements of magnetization reversal in an individual permalloy nanotube using a hybrid magnetometer consisting of a nanometer-scale SQUID and a cantilever torque sensor. The work is the result of fruitful collaborations between our group, the group of Prof. Dirk Grundler, the group of Profs. Dieter Koelle and Reinhold Kleiner, and the group of Prof. Anna Fontcuberta i Morral. Ph.D. students Arne Buchter and Marcus Wyss from our group were involved in the project.

End of the Year Dinner

On the 15th, the group joined the Warburton, Maletinsky, and Zardo groups for a holiday dinner at Der Vierte König in Basel. Thanks to Maletinsky group Ph.D. student Arne Barfuss for organizing. Happy holidays and happy new year to all!

Seminar at ETH Institute for Biomedical Engineering

On the 10th, Prof. Poggio gave a seminar at the ETH Institute for Biomedical Engineering in Zürich. The talk was entitled, “Nanometer-scale magnetometry” and was part of a series of seminars on Biomedical Magnetic Resonance. After the talk, the visit included discussions with Prof. Klaas Prüssmann and his colleagues as well as  a tour of the impressive facilities at the institute.

Group in Muttenzerkurve

On the 26th, group members attended the FC Basel – AC Fiorentina game at the Sankt Jacob-Park in Basel. Led by locals Marcus Wyss and Ben Herzog, Nicola Rossi, Floris Braakman, Denis Vasyukov, Boris Gross, and Martino Poggio rooted for the local team from the Muttenzerkurve.  The Europa League game ended 2-2.

Prof. Poggio at TecDay in Lugano

On the 20th, Prof. Poggio took part in the TecDay at the Liceo Cantonale di Lugano 2. The event, organized by the Swiss Academy of Engineering Sciences (SATW) gave high school students the chance to hear talks by researchers from both universities and industry about the latest advances in the natural and technical sciences. Prof. Poggio’s contribution, entitled “Nanotecnologia: come e perché”, sought to describe nanotechnology and what it’s for. More generally the talk discussed the role that size plays in determining the behavior and function of an object.

Prof. Istvan Kezsmarki Visits

Prof. Istvan Kezsmarki of the Department of Physics at Budapest University of Technology and Economics visited our group from the 2nd until the 4th. He gave a talk at the Nano and Quantum Physics Seminar on the 2nd entitled, “Néel-type skyrmion with a polar dressing”. Prof. Kezsmarki also participated in extended discussions with our group members over ongoing collaborative projects. We look forward to working together in the future!

Nanowires Workshop in Barcelona

Group members attended the Nanowires Workshop in Barcelona, Spain from the 26th to the 30th. This is the 7th in a successful series of annual workshops on the physics, chemistry and applications of nanowires. Post-doc Floris Braakman, Ph.D. students Davide Cadeddu and Nicola Rossi, and Prof. Poggio were in attendance. On the 29th, Davide gave a talk entitled, “A quantum fiber-pigtail”, Prof. Poggio gave a talk entitled, “Nanowires for sensing”, and Floris presented a poster entitled, “Nonlinear mechanical mode coupling and quantum dots in grown GaAs nanowires”.

Paper on Reducing Dissipation in Cantilevers Published

On the 26th, a paper entitled, Permanent reduction of dissipation in nanomechanical Si resonators by chemical surface protection, was published in the journal Nanotechnology. This work represents a collaboration between our lab and the lab of Prof. Christian Degen at ETH Zürich. The paper shows that mechanical energy dissipation in ultrasensitive Si cantilevers is a result of the amorphous nature of the oxide layers that rapidly form on Si. The work also identifies ways of preventing growth of this amorphous layer, thus allowing up to five-fold improvements to cantilever performance. A news article on the research appeared on nanotechweb.org and was highlighted on Nanotechnology Select.

Colloquium Speakers Visit the Lab

On Friday the 22nd, Prof. Erik Bakkers of the Eindhoven University of Technology and the Delft University of Technology gave the department’s Colloquium. The talk was titled, “New opportunities with nanowires”, and provided an excellent and much appreciated review of this timely topic with emphasis on the crystal growth aspects. One week later, Prof. Eli Zeldov gave another excellent talk at the Colloquium entitled, “Scanning SQUID-on-tip nanoscale magnetometry and thermometry”. The talk covered some very recent and impressive experimental results from Prof. Zeldov’s group in developing ultrasensitive scanning magnetic and thermal sensors. Both Prof. Bakkers and Prof. Zeldov were invited by our group and were given a tour of both the department and our labs.

Ph.D. Student Arne Buchter Graduates

On the 19th of October, Ph.D. student Arne Buchter defended his thesis and earned his physics doctorate magna cum laude. The examination was chaired by Prof. Richard Warburton with Prof. Poggio and Prof. Jean-Philippe Ansermet (EPFL) making up the committee. Arne joined the lab in July of 2011 and went on to start a his own research project combining cantilever magnetometry with nanometer-scale SQUID sensors. He carried the project through, successfully managing a large collaboration including various external groups and publishing his work in prestigious journals. His hard work and determination have paid off as he has already secured a job as a researcher at the Federal Institute of Metrology (METAS) in Bern. Congratulations to Dr. Buchter and good luck for the future!  We look forward to hearing about your future work!

Physik I für Biologen Starts

Together with Prof. Thomas Jung, Prof. Poggio is teaching “Physik I für Studierende der Biologie, Geowissenschaften und Pharmazeutische Wissenschaften” this semester. The lecture covers the basics of mechanics, fluid dynamics, and thermodynamics for non-physics science bachelor students. The first lecture of the semester is on September 17th.

SNI Annual Meeting

The annual meeting of the Swiss Nanoscience Institute (SNI) was held on the 3rd and 4th at the Hotel Schweizerhof in Lenzerheide, Switzerland. Ph.D student Davide Cadeddu and Prof. Poggio were in attendance and both gave talks entitled, “A quantum fiber-pigtail” and “Scanning nanowires sensors” respectively.

Poggio Lab / Machine Shop BBQ

On Friday the 14th, we held our annual barbecue together with our friends and colleagues from the Physics Department Machine Shop. Despite the drizzly weather, lab members, technicians, visitors, colleagues, friends, and alumni joined in the fun. Thanks especially to the Machine Shop and to Ph.D. students Andrea Mehlin and Marcus Wyss for organizing!

Floris Braakman wins Ambizione Grant

In mid-August, Dr. Floris Braakman won an Ambizone Grant from the Swiss National Science Foundation. Ambizione grants are aimed at young researchers who wish to conduct, manage, and lead an independent project at a Swiss higher education institution. The selection process includes a written proposal and an in-person interview. The funding includes salary and project funds for three years. Congratulations to Floris!

SpinTech VIII in Basel

The 8th International School and Conference on Spintronics and Quantum Information Technology (SpinTech VIII) was held in Basel from the 10th to the 13th. Dr. Floris Braakman, Arne Buchter, Andrea Mehlin, Nicola Rossi, Marcus Wyss, and Prof. Poggio attended the conference, which  highlighted fundamental physical phenomena related to spin-dependent effects in condensed matter and advances in the development of new spintronic materials, structures, and devices, including quantum information science and concepts. Arne, Andrea, and Marcus presented posters and Prof. Poggio gave a talk entitled, “Measuring nanometer-scale spins systems by ultrasensitive cantilever magnetometry”.

Group at NanoMRI Conference in Waterloo

Prof. Poggio, Dr. Boris Groß, Dr. Denis Vasyukov, Ben Herzog, and Davide Cadeddu attended the 5th Nanoscale Magnetic Resonance Imaging (NanoMRI) Conference in Waterloo, Canada from the 27th to the 31st.  The conference was held on the campus of the University of Waterloo at the Institute for Quantum Computing.  The event brought together an interdisciplinary community of scientists and engineers to discuss recent advances in and new techniques for NanoMRI. Three themes dominated the proceedings: Magnetic Resonance Force Microscopy (MRFM), Optically-Detected Magnetic Resonance (ODMR) using nitrogen vacancy (NV) centers, and quantum nano-mechanics. Ben Herzog presented a poster and Prof. Poggio gave a talk entitled, “Measuring nanometer-scale spins systems by ultrasensitive cantilever magnetometry” (video). Videos of nearly all the talks are available here.

Dr. Boris Groß Wins Goldener Korrekturstift

Post-doc Dr. Boris Groß has won the “Goldener Korrekturstift” (Gold Correction Pen) for his work as a teaching assistant in Physik II für Biologen this past spring semester. The prize is awarded each semester by the student group “Fachgruppe 14” to the assistant who receives the best student evaluations in a required physics lecture. Congratulations to Boris for a job well done!

Paper Reporting Cantilever Magnetometry of Skyrmions Published

On the 22nd, our paper entitled, Stabilized Skyrmion Phase Detected in MnSi Nanowires by Dynamic Cantilever Magnetometry, was published in Nano Letters as an ASAP Article. The paper presents measurements of dynamic cantilever magnetometry showing an enhanced skyrmion lattice phase extending from around 29 K down to at least 0.4 K in single MnSi nanowires (NWs). Although recent experiments on two-dimensional thin films show that reduced dimensionality stabilizes the skyrmion phase, our results are surprising given that the NW dimensions are much larger than the skyrmion lattice constant. Furthermore, the stability of the phase depends on the orientation of the NWs with respect to the applied magnetic field, suggesting that an effective magnetic anisotropy, likely due to the large surface-to-volume ratio of these nanostructures, is responsible for the stabilization. The compatibility of our technique with nanometer-scale samples paves the way for future studies on the effect of confinement and surfaces on magnetic skyrmions. The experiments were led here in Basel by Ph.D. student Andrea Mehlin and former post-doctoral researcher Prof. Fei Xue (now a PI at the High Magnetic Field Laboratory of the Chinese Academy of Sciences), who initiated the project. The NW samples were grown by the group of Prof. Song Jin at the University of Wisconsin.

Prof. Poggio in Munich

Prof. Poggio attended the Spin Mechanics 3 conference in Munich, Germany from the 22nd to the 26th.  The conference addressed the physics of interactions between spin angular momenta and mechanical degrees of freedom. Research related to these questions is spread across different areas of modern solid-state physics, including magnetism, spintronics, materials science, spectroscopy, nano-electromechanical systems, and scanning probe microscopy. Prof. Poggio gave the opening talk of the conference entitled, “Measuring nanometer-scale spin systems by ultrasensitive cantilever magnetometry”.

Bike Tour in Alsace

On Sunday the 14th, the group went on a bicycle tour of nearby Alsace, France. We enjoyed cycling the beautiful countryside, a hearty lunch, various stops for repairs, a short Frisbee break, and — to top it off — an generous wine sampling. Thanks to Ben Herzog, Marcus Wyss, and Andrea Mehlin for organizing a great outing!

Ph.D. Student Gives QSIT Lunch Seminar

On the 4th, Ph.D. student Andrea Mehlin gave a talk about her latest research as part of the QSIT Lunch Seminar at ETH Zürich. Her presentation was entitled, “Stabilized skyrmion phase detected in MnSi nanowires by dynamic cantilever magnetometry”.

Markus Ternes Visit

Dr. Markus Ternes from the Max Planck Institut in Stuttgart visited our group and the department on Monday the 18th. Dr. Ternes also gave a talk entitled, “Using scanning probe microscopes to detect and manipulate quantum magnetism and many particle states”, at the weekly QC2/QSIT Seminar.

Group Members in Meersburg

Post-doc Dr. Boris Groß and Ph.D. students Andrea Mehlin, Arne Buchter, and Marcus Wyss attended the International Workshop on Magnetic Nanowires and Nanotubes in Meersburg, Germany from the 17th to the 20th. After the first such workshop in 2013 in Kaub, Germany this was the second event bringing together groups working on magnetic nanowires and nanotubes. The workshop focused on magneto-transport in wire-like magnetic nanostructures, device fabrication, and new concepts for storage devices. Arne gave a talk on his most recent work, while  Boris and Andrea presented posters.

Denys Makarov Visit

Dr. Denys Makarov of the IFW Dresden visited us from Monday the 27th to Wednesday the 29th here in Basel. Dr. Makarov is a principal investigator and an expert on magnetism, magnetization reversal, and magneto-electronics. He gave an informal talk on Tuesday and discussed collaborative projects with our group.

Talk at IFW Dresden

On Friday the 13th, Prof. Poggio visited the Leibniz Institute for Solid State and Materials Research in Dresden, Germany on the invitation of Dr. Thomas Mühl. There he toured various laboratories, spoke with colleagues, and gave a seminar entitled, “Nanometer-scale cantilever magnetometry”, at the Institute for Solid State Research headed by Prof. Dr. Bernd Büchner. Thanks to all for some very stimulating discussions and for the hospitality.

Fundamental Electronics Begins

Prof. Poggio’s course entitled Fundamental Electronics is now underway. Lectures will be Tuesdays, 10.00-12.00 in Neuer Hörsaal 1. The practical sessions will take place once a week in Seminarzimmer 2.04. The schedule for these sessions is yet to be determined: stay tuned.

Group Highlighted in New Website

On Monday the 16th, the University of Basel took a step towards modernizing its image by replacing its prehistoric website with an improved version. Among the new features, is a section dedicated to nanosciences, which also highlights the work carried out in our lab.

Seminar in Stuttgart

On Tuesday the 10th, Prof. Poggio gave a seminar entitled, “Nanometer-scale cantilever magnetometry”, at the 3. Physikalisches Institut headed by Prof. Dr. Jörg Wrachtrup of the University of Stuttgart. Dr. Amit Finkler served as host and organized a tour of the laboratories. The institute boasts several impressive laboratories aimed at experiments in solid state quantum optics and spintronics with applications in modern microscopy, metrology, and biophysics. Thanks to all for the nice discussions and hospitality.

Joint Ph.D. Student Starts in the Lab

Panagiotis Fountas started work as a joint Ph.D. student between our group and the group of Prof. Stefan Willitsch in the Department of Chemistry. Panagiotis received both his Bachelor of Science in Chemistry and his Masters of Science in Physical Chemistry from the National and Kapodistrian University of Athens. His office will be in the Physical Chemistry building with the rest of the Willitsch Group, but he will work together with both research groups.

Workshop in Basel

On Thursday the 29th and Friday the 30th, our group hosted the “3rd Optical & Magnetic Nanostructures Workshop” here at the University of Basel. The two-day program aimed to generate discussion and collaboration between the participating groups, which included the Kölle Group (Tübingen), the Grundler Group (TU München), the Fontcuberta Group (EPFL), the Warburton group (Basel), and our own group. Additional participants included Prof. Jordi Arbiol (ICMAB-CSIC), Dr. Armin Kleibert (PSI), and Dr. Andás Kovács (Jülich). This year’s workshop, which follows previous editions in Lausanne (2014) and in Basel (2012), featured 17 talks, and 32 participants between PIs, post-docs, and Ph.D. students. Two separate themes dominated the discussions: “Nanowires & Quantum Dots” and “Nano-magnetometry”. Thanks to all of the participants for making a lively and successful workshop. Special thanks to Claudia Wirth for her work organizing such a smooth event. We hope to see you all again at the next edition!

Nano in the Snow

Ph.D. student Davide Cadeddu gave a talk at this year’s Swiss Nanoscience Institute (SNI) Winter School — known as “Nanoscience in the Snow 2015“.  The school took place from the 21st to the 23rd in Kandersteg, Switzerland. Davide’s talk was entitled, “Mechanical mode coupling and nonlinearity in as‐grown GaAs nanowires”. Thanks to Claudia Wirth and Michele Calamé for oganizing the meeting!

Dan Rugar Visits Basel

Dr. Dan Rugar from the IBM Almaden Research Center in San Jose, California visited our department on the 20th. Dan spent time with the Poggio Group, Maletinsky Group, and the Loss Group during his visit. He gave a special seminar in the afternoon entitled, “Progress in nanoscale nuclear magnetic resonance detection and imaging using NV centers in diamond”.

QSIT Meeting in Arosa

During the second week of January, Ph.D. students Davide Cadeddu, Nicola Rossi, and Marcus Wyss, along with post-docs Dr. Floris Braakman and Dr. Boris Groß attend the 5th NCCR QSIT General Meeting in Arosa, Switzerland. Davide presented a poster and Floris gave a talk.