Dear Colleagues, Please join us for a joint PQSEI/BNC/Spintronics seminar (details below). Please contact me if you wish to meet with Jana during her visit. She arrives on June 20th and departs on June 27th. Jana Lustikova Center for Science & Innovation in Spintronics (CSIS) and Advanced Institute for Materials Research (AIMR) Tohoku University Friday, June 21, 2019 1-2 p.m., PHYS 111 "Rectification effects in a superconducting vortex liquid with magnet proximity" Rectification appears in systems which exhibit a difference in resistivity depending on the polarity of the current, i.e. nonreciprocity, leading to a conversion of a d.c. input into an a.c. output. One of the requirements for rectification is broken inversion symmetry. In electronic systems, inversion symmetry has to be broken at atomic scale due to the short coherence length of electrons in condensed matter. As a result, electronic rectification effects are observed at interfaces and junctions [1] or in materials with noncentrosymmetric crystalline structure [2]. In this talk, I will report our observation of nonreciprocal resistivity and rectification in a vortex liquid phase of a superconducting material without lowered crystalline symmetry [3]. Superconducting vortices can be deleted or created only at the edges of the sample and their flow is a conserved quantity in the bulk. Owing to this property, nonreciprocal vortex flow can be realized just by imposing asymmetric magnetic environment on the edges of a specimen. We have used an amorphous superconducting alloy with weak vortex pinning, and by putting it close to the ferrimagnetic insulator Y3Fe5O12, successfully observed nonreciprocal electric resistivity. In addition, this system generates d.c. electric power from electromagnetic noise in the measurement equipment. [1] C.O. Avci et al., Nature Physics 11, 570 (2015). [2] T. Ideue et al., Nature Physics 13, 578 (2017). [3] J. Lustikova et al., Nature Communications 9, 4922 (2018). Thank you, Annie Wheeldon Administrative Assistant to the Director Purdue Quantum Science Engineering Institute Birck Nanotechnology Center 1205 W. State Street | West Lafayette, IN Office: 765.496.7425 | Email: acheever@purdue.edu<mailto:acheever@purdue.edu> [https://www.purdue.edu/brand/images/Purdue_University-150_Years_of_Giant_Lea...] www.purdue.edu/giantleaps<http://www.purdue.edu/giantleaps>
