BEGIN:VCALENDAR VERSION:2.0 PRODID:IEEE vTools.Events//EN CALSCALE:GREGORIAN BEGIN:VTIMEZONE TZID:America/Denver BEGIN:DAYLIGHT DTSTART:20250309T030000 TZOFFSETFROM:-0700 TZOFFSETTO:-0600 RRULE:FREQ=YEARLY;BYDAY=2SU;BYMONTH=3 TZNAME:MDT END:DAYLIGHT BEGIN:STANDARD DTSTART:20241103T010000 TZOFFSETFROM:-0600 TZOFFSETTO:-0700 RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=11 TZNAME:MST END:STANDARD END:VTIMEZONE BEGIN:VEVENT DTSTAMP:20250303T155947Z UID:00B607AB-1CBC-430D-9C7D-C27CD7B9BD5E DTSTART;TZID=America/Denver:20250228T110000 DTEND;TZID=America/Denver:20250228T120000 DESCRIPTION:In novel\, beyond Von Neumann\, computational approaches the us e of magnons (or quanta of spin waves) is particularly promising due to th e small intrinsic energies of individual magnons (μeV)\, the possibility of using phase\, in addition to magnitude\, as a state variable\, and the possibility to control the magnon dispersion properties in a magnetic samp le by varying the direction and magnitude of the bias magnetic field [1].\ n\nHowever\, the use of magnons in advanced and neuromorphic computing is severely limited by the existing linear methods of magnon excitation\, whi ch are based on current-driven inductive transducers which have poor energ y efficiency due to Ohmic losses\, and are unable to effectively excite ul tra-short exchange-dominated magnons. Here we propose to use a resonator-l ike energy-efficient gate\, based on the effect of voltage-controlled magn etic anisotropy (VCMA) [2]\, as a new type of antenna for parametric excit ation and reception of exchange-dominated magnons of a submicron wavelengt h\, having a well-defined phase. When a pumping voltage V of a microwave frequency is applied to a resonator-like VCMA gate\, the parametric excita tion of two short-wavelength counter-propagating half-pumping-frequency ma gnons and will occur\n\nThe magnetic anisotropy under the gate will be ch anged\, causing partial reflections of the excited magnons at the both gat e boundaries. The excited magnons\, then\, will have a well-defined phase\ , that is determined by the phase of the pumping voltage and by the reflec tion properties of the VCMA resonator. The wavenumber of the excited magno ns could be large\, and unrelated to the gate size\, as it is determined o nly by the pumping frequency\, and the magnon dispersion law . The same re sonator-like VCMA gate can also act as a receiver of propagating short-wav elength magnons that will create a standing wave under the gate with doubl e the magnon frequency. This standing wave of the frequency will be detect ed using a parametric confluence process opposite to the parametric splitt ing process (1) used for the excitation of magnons at the input VCMA gate. Our calculations show that the reflection of the excited magnons at the g ate boundaries reduces the excitation threshold up to two times (in the ca se of full reflection ). The calculated excitation threshold for the VCMA gate is presented in Fig. 1. In our calculations we used geometric parame ters that are typical for VCMA experiment made on Fe/MgO heterostructures (see e.g. [2\, 3]: thickness of the Fe waveguide \, thickness of dielectri c layer \, waveguide width \, and the length of the pumping gate . Our pre liminary numerical calculation performed for the simplified model of a vol tage-biased VCMA gate (see Fig. 1) have demonstrated that the proposed met hod of parametric excitation and reception of ultra-short-wavelength magno ns is realistic\, and can be implemented in experiment to generate phase-m odulated magnon signals of sub-micron wavelength with high energy efficien cy in the GHz and sub-THz frequency ranges.\n\n[1] A. Mahmoud\, F. Ciubota ru\, F. Vanderveken\, A. V. Chumak\, S. Hamdioui\, C. Adelmann\, and S. Co tofana\, "Introduction to spin wave computing\," Journal of Applied Physic s\, vol. 128\, no. 16\, p. 161101\, 2020.\n\n[2] P. Khalili Amiri and K. L . Wang\, "Voltage-controlled magnetic anisotropy in spintronic devices\," SPIN\, vol. 02\, no. 03\, p. 1240002\, 2012.\n\n[3] R. Tomasello\, R. Verb a\, V. Lopez-Dominguez\, F. Garesci\, M. Carpentieri\, M. Di Ventra\, P. K halili Amiri\, and G. Finocchio\, "Antiferromagnetic Parametric Resonance Driven by Voltage-Controlled Magnetic Anisotropy\," Physical Review Applie d\, vol. 17\, no. 3\, p. 034004\, 2022.\n\nCo-sponsored by: UCCS\n\nSpeake r(s): Andrei Slavin\n\nRoom: A204\, Bldg: Osborne Center for Science and E ngineering\, 1420 Austin Bluffs Pkwy\, Colorado Springs\, Colorado\, Unite d States\, 80918\, Virtual: https://events.vtools.ieee.org/m/461172 LOCATION:Room: A204\, Bldg: Osborne Center for Science and Engineering\, 14 20 Austin Bluffs Pkwy\, Colorado Springs\, Colorado\, United States\, 8091 8\, Virtual: https://events.vtools.ieee.org/m/461172 ORGANIZER:eiacocca@uccs.edu SEQUENCE:9 SUMMARY:Resonator-Like Antenna for Parametric Excitation of Ultra-Short Spi n Waves URL;VALUE=URI:https://events.vtools.ieee.org/m/461172 X-ALT-DESC:Description: <br /><p class="MsoNormal" style="mso-margin-top-al t: auto\; mso-margin-bottom-alt: auto\; text-align: justify\; line-height: normal\;"><span style="font-size: 10.0pt\; font-family: 'Times New Roman' \,serif\; mso-fareast-font-family: 'Times New Roman'\; mso-font-kerning: 0 pt\; mso-ligatures: none\;">In novel\, <span style="mso-bidi-font-weight: bold\;">beyond Von Neumann\, computational approaches</span> the use of <e m>magnons </em>(or quanta of spin waves) <span style="mso-bidi-font-weight : bold\;">is particularly promising due to the small intrinsic energies of individual magnons (&mu\;eV)\, the possibility of using phase\, in additi on to magnitude\, as a state variable\, and the possibility to control the magnon dispersion properties in a magnetic sample by varying the directio n and magnitude of the bias magnetic field [1].</span><span style="mso-spa cerun: yes\;">&nbsp\; </span></span></p>\n<p class="MsoNormal" style="mso- margin-top-alt: auto\; mso-margin-bottom-alt: auto\; text-align: justify\; line-height: normal\;"><span style="font-size: 10.0pt\; font-family: 'Tim es New Roman'\,serif\; mso-fareast-font-family: 'Times New Roman'\; mso-fo nt-kerning: 0pt\; mso-ligatures: none\;"><span style="mso-spacerun: yes\;" >&nbsp\;&nbsp\;&nbsp\;&nbsp\; </span>However\, the use of magnons in advan ced and neuromorphic computing is severely limited by the existing linear methods of magnon excitation\, which are based on current-driven inductive transducers which have poor energy efficiency due to Ohmic losses\, and a re unable to effectively excite ultra-short exchange-dominated magnons. He re we propose to use a resonator-like energy-efficient gate\, based on the effect of voltage-controlled magnetic anisotropy (VCMA) [2]\, as a new ty pe of antenna for parametric excitation and reception of exchange-dominate d magnons of a submicron wavelength\, having a well-defined phase. <span s tyle="mso-bidi-font-weight: bold\;"><span style="mso-spacerun: yes\;">&nbs p\;</span></span>When a pumping voltage <em>V</em> of a microwave frequenc y is applied to a resonator-like VCMA gate\, the parametric excitation of two short-wavelength counter-propagating half-pumping-frequency magnons </ span><span style="font-size: 12.0pt\; font-family: 'Times New Roman'\,seri f\; mso-fareast-font-family: 'Times New Roman'\; mso-font-kerning: 0pt\; m so-ligatures: none\;"><span style="mso-spacerun: yes\;">&nbsp\;</span>and </span><span style="font-size: 10.0pt\; font-family: 'Times New Roman'\,se rif\; mso-fareast-font-family: 'Times New Roman'\; mso-font-kerning: 0pt\; mso-ligatures: none\;">will occur</span></p>\n<p class="MsoNormal" style= "mso-margin-top-alt: auto\; mso-margin-bottom-alt: auto\; text-align: just ify\; line-height: normal\;"><span style="font-size: 10.0pt\; font-family: 'Times New Roman'\,serif\; mso-fareast-font-family: 'Times New Roman'\; m so-font-kerning: 0pt\; mso-ligatures: none\;">The magnetic anisotropy unde r the gate will be changed\, causing partial reflections of the excited ma gnons at the both gate boundaries. The excited magnons\, then\, will have a well-defined phase\, that is determined by the phase of the pumping volt age and by the reflection properties of the VCMA resonator. The wavenumber of the excited magnons could be large\, and unrelated to the gate size\, as it is determined only by the pumping frequency\, and the magnon dispers ion law . The same resonator-like VCMA gate can also act as a receiver of propagating short-wavelength magnons that will create a standing wave unde r the gate with double the magnon frequency. This standing wave of the fre quency will be detected using a parametric confluence process opposite to the parametric splitting process (1) used for the excitation of magnons at the input VCMA gate. Our calculations show that the reflection of the exc ited magnons at the gate boundaries reduces the excitation threshold up to two times (in the case of full reflection <span style="mso-spacerun: yes\ ;">&nbsp\;</span>). The calculated excitation threshold for the VCMA gate is presented in Fig.&nbsp\;1. In our calculations we used geometric parame ters that are typical for VCMA experiment made on Fe/MgO heterostructures (see e.g. [2\, 3]: thickness of the Fe waveguide \, thickness of dielectri c layer <span style="mso-bidi-font-style: italic\;">\, waveguide width </s pan>\, and the length of the pumping gate .<span style="mso-spacerun: yes\ ;">&nbsp\; </span>Our preliminary numerical calculation performed for the simplified model of a voltage-biased VCMA gate (see Fig. 1) have demonstra ted that the proposed method of parametric excitation and reception of ult ra-short-wavelength magnons is realistic\, and can be implemented in exper iment to generate phase-modulated magnon signals of sub-micron wavelength with high energy efficiency in the GHz and sub-THz frequency ranges.&nbsp\ ;</span></p>\n<p class="MsoBodyText"><span style="font-size: 10.0pt\; mso- bidi-font-weight: bold\;">[1]</span><span style="mso-bidi-font-size: 10.0p t\; mso-no-proof: yes\;"> </span><span style="font-size: 10.0pt\; mso-bidi -font-weight: bold\;">A. Mahmoud\, F. Ciubotaru\, F. Vanderveken\, A. V. C humak\, S. Hamdioui\, C. Adelmann\, and S. Cotofana\, "Introduction to spi n wave computing\," <em style="mso-bidi-font-style: normal\;">Journal of A pplied Physics\, </em>vol. 128\, no. 16\, p. 161101\, 2020.</span></p>\n<p class="MsoBodyText"><span style="font-size: 10.0pt\;">[2]</span><span sty le="mso-bidi-font-size: 10.0pt\; mso-no-proof: yes\;"> </span><span style= "font-size: 10.0pt\;">P. Khalili Amiri and K. L. Wang\, "Voltage-controlle d magnetic anisotropy in spintronic devices\," <em style="mso-bidi-font-st yle: normal\;">SPIN\, </em>vol. 02\, no. 03\, p. 1240002\, 2012.</span></p >\n<p class="MsoBodyText"><span style="font-size: 10.0pt\;">[3] R. Tomasel lo\, R. Verba\, V. Lopez-Dominguez\, F. Garesci\, M. Carpentieri\, M. Di V entra\, P. Khalili Amiri\, and G. Finocchio\, "Antiferromagnetic Parametri c Resonance Driven by Voltage-Controlled Magnetic Anisotropy\," <em style= "mso-bidi-font-style: normal\;">Physical Review Applied\, </em>vol. 17\, n o. 3\, p. 034004\, 2022.</span></p> END:VEVENT END:VCALENDAR