{"id":107,"date":"2023-01-16T13:33:58","date_gmt":"2023-01-16T13:33:58","guid":{"rendered":"https:\/\/wp.icmm.csic.es\/seminars\/?p=107"},"modified":"2023-02-15T11:16:03","modified_gmt":"2023-02-15T11:16:03","slug":"akashdeep-kamra-16-02-2023","status":"publish","type":"post","link":"https:\/\/wp.icmm.csic.es\/seminars\/2023\/01\/16\/akashdeep-kamra-16-02-2023\/","title":{"rendered":"Akashdeep Kamra (16\/02\/2023)"},"content":{"rendered":"

\"\"<\/h2>\n

<\/h2>\n

Akashdeep Kamra,\u00a0<\/strong>Universidad Autonoma de Madrid<\/em><\/h2>\n

The magnon-cooparon quasiparticle<\/h2>\n

Generating and moving unconventional spinal Cooper pairs using magnons<\/h4>\n

<\/h4>\n

When: 12:00-13:00 CET, February 16th (Thursday), 2023<\/h4>\n

Where: Seminar Room, ICMM-CSIC, Campus de Cantoblanco, Madrid<\/h4>\n

A superconductor is formed when pairs of electrons undergo condensation into a macroscopically\u00a0coherent state with a common order parameter. Its supporting dissipationless flow of charge\u00a0currents underlies the central role that superconductors are playing in various emerging quantum\u00a0technologies. The widely used conventional superconductors are constituted by spin-singlet Cooper\u00a0pairs. These are formed by electrons bearing opposite spin, and therefore bear no net spin. For\u00a0various phenomena, such as dissipationless magnetic memories and Majorana excitations, it is\u00a0desirable to have equal-spin triplet Cooper pairs formed by electrons with the same spin.\u00a0Engineering and controlling such exotic Cooper pairs has thus been a main goal and challenge for\u00a0the scientific community [1].<\/p>\n

In this talk, we will discuss some recent theoretical efforts in achieving the generation and control\u00a0of such spin-triplet Cooper pairs using magnetic insulators and their spin excitations \u2013 magnons. We\u00a0will show that if the superconductivity is mediated by antiferromagnetic magnons, instead of\u00a0phonons, the resulting superconducting state is unconventional and can achieve a relatively high\u00a0critical temperature [2,3]. This can be accomplished in bilayers comprising an antiferromagnetic\u00a0insulator (AFI) interfaced to a normal metal. Furthermore, unconventional N\u00e9el spin-triplet Cooper\u00a0pairs with pairing amplitude oscillating at atomic length scales have recently been predicted to\u00a0emerge in AFI\/superconductor bilayers [4]. Finally, we will discuss the emergence of a novel\u00a0quasiparticle \u2013 magnon-cooparon \u2013 in a conventional superconductor interfaced with a\u00a0ferromagnetic insulator [5]. The spatially inhomogeneous exchange field generated by a magnon in\u00a0the ferromagnet induces spin-triplet Cooper pairs in the adjacent superconductor which act to screen\u00a0the magnon spin. This quasiparticle, reminiscent of the polaron excitation, allows driving the spin-triplet Cooper pairs in a desired direction employing mature techniques from the field of\u00a0magnonics. The magnon-cooparon also enables a powerful magnonic directional coupler, a key\u00a0element in magnon-based logic and computing paradigms.<\/p>\n

References:<\/strong><\/p>\n

[1] Matthias Eschrig. Spin-polarized supercurrents for spintronics: a review of current progress.\u00a0Rep. Prog. Phys. 78, 104501 (2015).
\n[2] A. Kamra, A. Rezaei, and W. Belzig. Spin splitting induced in a superconductor by an
\nantiferromagnetic insulator. Phys. Rev. Lett. 121, 247702 (2018).
\n[3] E. Erlandsen, A. Kamra, A. Brataas, and A. Sudb\u00f8. Enhancement of superconductivity
\nmediated by antiferromagnetic squeezed magnons. Phys. Rev. B 100, 100503(R) (2019).
\n[4] G. A. Bobkov, I. V. Bobkova, A. M. Bobkov, and A. Kamra. N\u00e9el proximity effect at
\nantiferromagnet\/superconductor interfaces. Phys. Rev. B 106, 144512 (2022). \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0[5] I. V. Bobkova, A. M. Bobkov, A. Kamra, and W. Belzig. Magnon-cooparons in magnet-
\nsuperconductor hybrids. Communications Materials 3, 95 (2022).<\/p>\n","protected":false},"excerpt":{"rendered":"

Akashdeep Kamra,\u00a0Universidad Autonoma de Madrid The magnon-cooparon quasiparticle Generating and moving unconventional spinal Cooper pairs using magnons When: 12:00-13:00 CET, February 16th (Thursday), 2023 Where: Seminar Room, ICMM-CSIC, Campus de Cantoblanco, Madrid A superconductor is formed when pairs of electrons undergo condensation into a macroscopically\u00a0coherent state with a common order parameter. Its supporting dissipationless flow … Continue reading Akashdeep Kamra (16\/02\/2023)<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":103,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-107","post","type-post","status-publish","format-standard","hentry","category-sin-categoria"],"_links":{"self":[{"href":"https:\/\/wp.icmm.csic.es\/seminars\/wp-json\/wp\/v2\/posts\/107","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wp.icmm.csic.es\/seminars\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wp.icmm.csic.es\/seminars\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wp.icmm.csic.es\/seminars\/wp-json\/wp\/v2\/users\/103"}],"replies":[{"embeddable":true,"href":"https:\/\/wp.icmm.csic.es\/seminars\/wp-json\/wp\/v2\/comments?post=107"}],"version-history":[{"count":1,"href":"https:\/\/wp.icmm.csic.es\/seminars\/wp-json\/wp\/v2\/posts\/107\/revisions"}],"predecessor-version":[{"id":110,"href":"https:\/\/wp.icmm.csic.es\/seminars\/wp-json\/wp\/v2\/posts\/107\/revisions\/110"}],"wp:attachment":[{"href":"https:\/\/wp.icmm.csic.es\/seminars\/wp-json\/wp\/v2\/media?parent=107"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wp.icmm.csic.es\/seminars\/wp-json\/wp\/v2\/categories?post=107"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wp.icmm.csic.es\/seminars\/wp-json\/wp\/v2\/tags?post=107"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}