Emission of coherent THz magnons in an antiferromagnetic insulator triggered by ultrafast spin–phonon interactions

Antiferromagnetic materials have been proposed as new types of narrowband THz spintronic devices owing to their ultrafast spin dynamics. Manipulating coherently their spin dynamics, however, remains a key challenge that is envisioned to be accomplished by spin-orbit torques or direct optical excitations. Here, we demonstrate the combined generation of broadband THz (incoherent) magnons and narrowband (coherent) magnons at 1 THz in low damping thin films of NiO/Pt. We evidence, experimentally and through modeling, two excitation processes of spin dynamics in NiO: an off-resonant instantaneous optical spin torque in (111) oriented films and a strain-wave-induced THz torque induced by ultrafast Pt excitation in (001) oriented films. Both phenomena lead to the emission of a THz signal through the inverse spin Hall effect in the adjacent heavy metal layer. We unravel the characteristic timescales of the two excitation processes found to be 300 fs, respectively, and thus open new routes towards the development of fast opto-spintronic devices based on antiferromagnetic materials

The Grizzly, February 26, 1982

Beta Sig Fears Charter Revocation • Wegman Graduates Valedictorian of Class of \u2782 • $3,000 of Stolen Equipment Recovered • Volleyball Marathon Raises$600 for Special Olympics • Beginning of a Warless World • Library Friends Donate Lisle Papers • Medical Health Care in the United States • Intaglio Prints at Myrin • Band Plays Best Coffeehouse • Scholarship Competition Announced • Arts & Culture Abound This Week • Frat Pledge Classes of 1982 • Learn to Swim • Tri-Captains Triumphvirate • Overseas Hockey • Men\u27s Swimming Ends 7-3 • Men, Women Hoopsters Roll to MAC • Matmen Take Ninth • Strizki, Cantello Qualifyhttps://digitalcommons.ursinus.edu/grizzlynews/1074/thumbnail.jp

Unconventional anomalous Hall effect in 3d/5d multilayers mediated by the nonlocal spin-conductivity

We evidenced unconventionnal Anomalous Hall Effects (AHE) in 3d/5d (Co0.2nm/Ni0.6nm)N multilayers grown on a thin Pt layer or thin Au:W alloy. The inversion observed on AHE originates from the opposite sign of the spin-orbit coupling of Pt compared to Ni. Via advanced simulations methods for the description of the spin-current profiles based on the spin-dependent Boltzmann formalism, we extracted the spin Hall angle (SHA) of Pt and (Co/Ni) as well as the relevant transport parameters. The extracted SHA for Pt, +20%, is opposite to the one of (Co/Ni), giving rise to an effective AHE inversion for thin (Co/Ni) multilayers (N < 17). The spin Hall angle in Pt is found to be larger than the one previously measured in combined spin-pumping inverse spin-Hall effect experiments in a geometry of current perpendicular to plane. Whereas magnetic proximity effects cannot explain the effect, spin-current leakage and anisotropic electron scattering at Pt/(Co,Ni) interfaces fit the experiments.Comment: 7 pages, 2 figure

The Grizzly, November 20, 1981

Ursinus Takes First Step As Planning Gets Under Way • Successful Graduates Advise Seniors • Whatley Invited to Shuttle Launch • Ursinus\u27 Tuition Compared to Other Colleges • Sleigh Bells in September • Annual Messiah Concert Dec. 5 • Study Abroad Series: \u27Of Pints and Men\u27 • Variety Briefs: One-man band; Chamber orchestra performs; Cafe international • USGA Notes • Girls B-Ball Optimistic For New Season • Aquamen Drop Opener • Grapplers Do Well • Men\u27s B-Ball...Can They Do It Again? • Fine Showing in Regionals Sends Team to Wisconsin • Girls Splash to Victoryhttps://digitalcommons.ursinus.edu/grizzlynews/1068/thumbnail.jp

Quantifying orbital Rashba effect via harmonic Hall torque measurements in transition-metal|Cu|Oxide structures

Spin-orbit interaction (SOI) plays a pivotal role in the charge-to-spin conversion mechanisms, notably the spin Hall effect involving spin-dependent deflection of conduction electrons and the interfacial spin Rashba-Edelstein effect. In recent developments, significant current-induced torques have been predicted and observed in material systems featuring interfaces with light elements \textit{i.e.} possessing a weak SOI. These findings challenge existing mechanisms and point to the potential involvement of the orbital counterpart of electrons, namely the orbital Hall and orbital Rashba effects. Here, we establish, in Pt|Co|Cu|AlOx stacking, the comparable strength between the orbital Rashba effect at the Cu|AlOx interface and the effective spin Hall effect in Pt|Co. Subsequently, we investigate the thickness dependence of an intermediate Pt layer in Co|Pt|Cu|CuOx, revealing the strong signature of the orbital Rashba effect at the Cu|CuOx interface besides the well-identified Pt intrinsic spin Hall effect. Leveraging such contribution from the orbital Rashba effect, we show a twofold enhancement in the effective torques on Co through harmonic Hall measurements. This result is corroborated by complementary spin Hall magneto-resistance and THz spectroscopy experiments. Our results unveil unexplored aspects of the electron's orbital degree of freedom, offering an alternative avenue for magnetization manipulation in spintronic devices with potential implications for energy-efficient and environmentally friendly technologies using abundant and light elements.Comment: 11 pages, 5 figure

The Grizzly, March 4, 1983

Zeta Chi Suspended: Fraternity Disciplined for Pledging Violations • Symposium Topics Discussed • New Forum Committee to Revise System • Letters to the Editor: Alumnus Responds to Grizzly Policy • Committee Reviews Appeals Procedure • Meistersingers Tour • Exam Schedule • Woodcuts at Myrin • Stravinsky Program Ends Winterfest • Lantern Deadline Approaches • Lewis on Wall Street • Alpha Sigma Nu Tops GPAs • Roving Reporter: The Administration is Proposing to put a Live-in Dean in 97 of New Men\u27s Dorm • Pre-Legal Society Resurrected • Swimmers Perform Beyond Expectation • Bear Blades Blaze to Victory • Gymnasts Draw No. 2 Ratinghttps://digitalcommons.ursinus.edu/grizzlynews/1096/thumbnail.jp

The Grizzly, November 19, 1982

Dorm Intrusion: Attack Prompts Security Changes • Council Approves Precalc • Student Apathy: Who Cares? • Elephants and Donkeys Revived on Campus • President\u27s Corner • Pledging Changes Planned • Commentary: Be a Good Boy, Johnny - Take Back Your Tray • Lewis on Wall Street • Applying for the Job • Robert Hazard: The Grizzly Interview • Final Exam Schedule • Grizzly Paws Boost Football Program • Women\u27s Basketball Set to Have Big Season • X-Country Takes a Disappointing Sixth • Soccer Team Was Tough All Year • Men\u27s Swimming Falls to Dickinson in Openerhttps://digitalcommons.ursinus.edu/grizzlynews/1089/thumbnail.jp

The Grizzly, February 12, 1982

Administration Keeping an Eye on Pledging • Housing System Under One Roof • Sororities Dance for Charity • UC College Bowl Impressive at Moravian • Comment: A Letter to Dr. Kane • USGA Notes • Legend Behind Lorelei • FCA Marathon for Special Olympics • Winterfest Tickets Available for Students • Forum on Rising Medical Costs • President\u27s Corner: The Biologist and the Poet • Concert Review: JT, Somehow Perfect; Cars, Shakin\u27 It Up • Vanities Auditions • Soft Core Culture • Frats Converge for Bid Day • Sports Briefs: W\u27s Swimming Gets Revenge; Aquabears Down Swarthmore; Dreamers and Jamas Undefeated • Matmen Run With Streak to Six • Women Crush Cabrini, 78-62 • Men\u27s B-Ball Takes Twohttps://digitalcommons.ursinus.edu/grizzlynews/1072/thumbnail.jp

The Grizzly, February 18, 1983

Rally at Bomberger: Students Protest Criticism • Rushes, Administration Meet Before Pledging • Editorial: Staff Members Defend Grizzly • USGA Notes • Letters to the Editor: Letter to the Editor Receives Support; Constructive Criticism Appreciated; Student Interest Sparked; Irresponsible Groups Cause Anger • Is Reaganomics a Reality? • Admissions Standards at Ursinus • President\u27s Corner • Happy Birthday to U • Talent Show Tonight • Occupational Hazards • Fighting Ursini Head to MACs Optimistically • Inconsistency Still Haunting Women\u27s Basketball • Gymnastics Ranked 13th • Badminton Team Tops Rosemont and Moravian • Lady Swimmers Boast 9-1 Record • Werley\u27s Record Speaks for Itselfhttps://digitalcommons.ursinus.edu/grizzlynews/1094/thumbnail.jp