Nanoscale magnetic and thermal imaging in quantum systems

NanoSQUIDs residing on the apex of a quartz tip (SOT), suitable for scanning probe microscopy with record size, spin sensitivity, and thermal sensitivity are presented[1,2] . We have developed SOT with an effective diameter smaller than 50 nm, spin sensitivity better than a single electron spin and thermal sensitivity better than 1 μK/Hz1/2 . This technique is used to study nanoscale magnetism present in systems such as atomically sharp LaMnO3/SrTiO3 (LMO/STO) heterostructures[3] and to study dissipation mechanism in quantum system such as hBN-encapsulated graphene[2,4] . Magnetic imaging of LMO/STO revealed a superparamagnetic behavior resulting from an electronic phase separation leading to nucleation of metallic ferromagnetic islands in an insulating antiferromagnetic matrix. Thermal imaging of hBN-encapsulated graphene reveals a fascinating atomic-scale dissipation mechanism providing visualization and control of phonon emission from inelastic electron scattering off individual atomic defects[4] , opening the door to direct imaging and spectroscopy of dissipation processes in quantum systems.

[1] D. Vasyukov, Y. Anahory, L. Embon, D. Halbertal, J. Cuppens, L. Neeman, A. Finkler, Y. Segev, Y. Myasoedov, M. L. Rappaport, M. E. Huber, and E. Zeldov, Nature Nanotech. 8, 639 (2013)

[2] D. Halbertal, J. Cuppens, M. Ben Shalom, L. Embon, N. Shadmi, Y. Anahory, H. R. Naren, J. Sarkar, A. Uri, Y. Ronen, Y. Myasoedov, L. S. Levitov, E. Joselevich, A. K. Geim, and E. Zeldov, Nature 539, 407 (2016).

[3] Y. Anahory, L. Embon, C. J. Li, S. Banerjee, A. Meltzer, H. R. Naren, A. Yakovenko, J. Cuppens, Y. Myasoedov, M. L. Rappaport, M. E. Huber, K. Michaeli, T. Venkatesan, and E. Zeldov, Nature Communications 8, 85 (2016)

[4] D. Halbertal, M. Ben Shalom, A. Uri, K. Bagani, A.Y. Meltzer, I. Marcus, Y. Myasoedov, J. Birkbeck, L.S. Levitov, A.K. Geim, and E. Zeldov, Science 358, 1303 (2017).