quantum phenomena; quantum tunneling; quantum coherence and oscillations; nanomagnetism; Magnetometry; Scanning Probe magnetometry; magnetic pump-probe experiments; ultra-low temperatures; magnetic vector fields; quantum magnetism; spintronics; magnetization dynamics; optomechanical systems
Babkevich P., Jeong M., Matsumoto Y., Kovacevic I., Finco A., Toft-Petersen R., Ritter C., Mansson M., Nakatsuji S., Ronnow H. M. (2016), Dimensional Reduction in Quantum Dipolar Antiferromagnets, in PHYSICAL REVIEW LETTERS
, 116(19), 197202.
Nilsen G. J., Araja A., Tsirlin A. A., Mutka H., Kasinathan D., Ritter C., Ronnow H. M. (2015), One-dimensional quantum magnetism in the anhydrous alum KTi(SO4)(2), in NEW JOURNAL OF PHYSICS
, 17, 113035.
Jeong M., Ronnow H. M. (2015), Quantum critical scaling for a Heisenberg spin-1/2 chain around saturation, in Phys. Rev. B
, 92, 180409.
Kumar R., Khuntia P., Sheptyakov D., Freeman P. G., Ronnow H. M., Koteswararao B., Baenitz M., Jeong M., Mahajan A. V. (2015), Sc2Ga2CuO7: A possible quantum spin liquid near the percolation threshold, in PHYSICAL REVIEW B
, 92(18), 180411.
Karci Ozgur, Piatek Julian O., Jorba Pau, Dede Munir, Ronnow Henrik M., Oral Ahmet (2014), An ultra-low temperature scanning Hall probe microscope for magnetic imaging below 40 mK, in REVIEW OF SCIENTIFIC INSTRUMENTS
, 85(10), 103703.
Piatek J. O., Kovacevic I., Babkevich P., Piazza B. Dalla, Neithardt S., Gavilano J., Kraemer K. W., Ronnow H. M. (2014), Nonequilibrium hysteresis and spin relaxation in the mixed-anisotropy dipolar-coupled spin-glass LiHo0.5Er0.5F4, in PHYSICAL REVIEW B
, 90(17), 174427.
Kasinathan Deepa, Koepernik K., Janson O., Nilsen G. J., Piatek J. O., Ronnow H. M., Rosner H. (2013), Electronic structure of KTi(SO4)(2)center dot H2O: An S=1/2 frustrated chain antiferromagnet, in PHYSICAL REVIEW B
, 88(22), 224410.
de Vries M. A., Piatek J. O., Misek M., Lord J. S., Ronnow H. M., Bos J-W G. (2013), Low-temperature spin dynamics of a valence bond glass in Ba2YMoO6, in NEW JOURNAL OF PHYSICS
, 15, 043024.
Piatek J. O., Dalla Piazza B., Nikseresht N., Tsyrulin N., Zivkovic I., Kraemer K. W., Laver M., Prokes K., Matas S., Christensen N. B., Ronnow H. M. (2013), Phase diagram with an enhanced spin-glass region of the mixed Ising-XY magnet LiHoxEr1-xF4, in PHYSICAL REVIEW B
, 88(1), 014408.
Kraemer Conradin, Nikseresht Neda, Piatek Julian O., Tsyrulin Nikolay, Dalla Piazza Bastien, Kiefer Klaus, Klemke Bastian, Rosenbaum Thomas F., Aeppli Gabriel, Gannarelli Che, Prokes Karel, Podlesnyak Andrey, Straessle Thierry, Keller Lukas, Zaharko Oksana, Kraemer Karl W., Ronnow Henrik M. (2012), Dipolar Antiferromagnetism and Quantum Criticality in LiErF4, in SCIENCE
, 336(6087), 1416-1419.
This proposal aims at acquiring a state of the art low-temperature facility (dilution refrigerator) specifically equipped to provide high cooling power (400microW) with ultra-low base temperature below 10mK, in combination with a specially designed high field superconducting vector-cryomagnet with unmatched field stability and accuracy. The applicant group is formed by 3 new professors at EPFL focusing on different activities at the forefronts of the overarching topic of quantum functionality in condensed matter: M. Kläui (Laboratory of Nanomagnetism and Spin Dynamics), H. M. Ronnow (Laboratory for Quantum Magnetism) and T. Kippenberg (Laboratory of Photonics and Quantum Measurements). In addition to the scientific synergies, which have been strengthened by the formation of the new Institute of Condensed Matter Physics, our activities share common infrastructure needs - most notably measurements in magnetic fields at ultra-low temperatures.Scientifically, a strong emphasis will be put on macroscopic quantum effects occurring in magnetic systems and we will study in particular the transition from classical spin dynamics to quantum tunnelling of domain walls. By correlating the tunnelling parameters and geometry as well as the wall spin structure, key information about magnetic properties, the potential landscape, and the dissipation channels will be ascertained. Beyond tunnelling we will study macroscopic quantum coherence effects, such as Bloch oscillations of domain walls occurring at mK temperatures in superlattices. Magnetic edge states will be probed in graphene nanostructures synthesized by a bottom-up chemical approach. We will study the effects on the spin transport, possible half-metallic behaviour and eventually use such nanoribbons for qubits.Bulk quantum magnets will be studied along 3 main directions: i) exploration of new model materials with novel quantum phases; ii) high precision studies of quantum phase transitions, and iii) magnetic pump-probe type measurements of non-equilibrium properties. The latter will address the surge of theoretical interest in so-called quantum quenches. While technically very challenging, it can open the gates to a new paradigm of experiments in quantum magnetism.Finally, the third applicant is among the world leaders in the new field of cavity optomechanics, which studies the coupling of light to mechanical degrees of freedom. This coupling has allowed to achieve measurements at the quantum limit of mechanical motion. The high cooling power low base-temperature system will allow to pursue the enigmatic goal of ground state cooling a microscopic system.In addition to serving the applicants’ research programs, the competitive temperature-field range combined with several advanced measurement possibilities including high frequencies and high pressures will make it a unique attraction welcoming collaborating groups from within Switzerland and beyond.