Conveners
W-POS-G #57-74 Poster session (Mag.North) / Session d'affiches (Nord mag.)
- Bruce Gaulin (McMaster University)
W-POS-G #57-74 Poster session (Mag.North) / Session d'affiches (Nord mag.)
- Bruce Gaulin (McMaster University)
The ability to image magnetodynamics has proved key to the advancement of spintronics technology [1]. As technological size scales reduce and speeds increase, there is a need to provide commensurate advancement in experimental tools to image magnetodynamics down to the atomic scale with ultrafast time resolution. In pursuit of this goal, we are developing a custom designed scanning tunneling...
Recently, there has been an increasing interest in the study of optical/microwave cavity-confined photon-magnon interaction due to their potential applications in quantum information processing and spintronics [1,2]. In those studies, a number of unique features have been observed at frequencies in the GHz range. On the other hand, less is known about the dynamics of...
Geometrical frustration arises in systems whose structures support multiple degenerate ground states. Artificial spin ice (ASI), has been built in diverse configurations which allows us to control frustration by experimentally tuning suitable parameters[1]. We present computational results on ASI systems consisting
of planar arrays of nanosized elongated ferromagnetic islands where...
Bulk spinel vanadate crystals are structurally cubic and ferrimagnetic, with biaxial anisotropy along the cubic axes. However, for thin film Cobalt Vanadate, an orthorhombic crystal structure leads to very different and stronger magnetic anisotropies. Data from torque magnetometry shows a uniaxial anisotropy with the magnetic easy axis shifting from out-of-plane at high temperatures, to...
The discovery of time-reversal symmetry(TRS) breaking in elemental Re has ignited fresh interest in the Re based superconductors. The recent studies show that role of Re concentration and crystal symmetry is crucial in understanding the unconventional superconductivity of these compounds. Therefore, we studied two Re-based superconductors Re$_3$B (<var>TC</var> = 5.19 K) and...
The Kitaev model on the honeycomb lattice recently attracted considerable attention. However, in candidate materials, other interactions are present, and
among them the off-diagonal $\Gamma$ interaction has been particularly challenging. While several numerical studies on a minimal Kitaev-$\Gamma$ $(K\Gamma)$ model found multiple quantum disordered phases, definite conclusions on existence...
The simplest example of geometric frustration is found in the two-dimensional triangular lattice. While the ground state of the Heisenberg model in this lattice is known to be Néel ordered, some recent low-temperature experiments on various triangular lattice compounds have unambiguously demonstrated the presence of short-range ordering, continuous excitation spectra, and non-trivial spin...
The Kosterlitz-Thouless (KT) transition is a topological transition in a model where magnetic vortex and antivortex spin structures are created in an infinite, isotropic, 2D magnetic system. The transition occurs when bound vortex-antivortex pairs unbind due to thermal energy at the temperature $T_{KT}$, and is marked by a magnetic susceptibility that diverges at low temperature, and...
Dynamical backaction resulting from radiation pressure forces in optomechanical systems has proven to be a versatile tool for manipulating mechanical vibrations. Notably, dynamical backaction has resulted in the cooling of a mechanical resonator to its ground-state, driving phonon lasing, and observing the optical-spring effect. In certain magnetic materials, mechanical vibrations can interact...
By engineering an anti-parity-time (anti-PT) symmetric cavity magnonics system with precise eigenspace controllability, we observe two different singularities in the same system. One type of singularity, the exceptional point (EP), is produced by tuning the magnon damping. Between two EPs, the maximal coherent superposition of photon and magnon states is robustly sustained by the preserved...
The classical Einstein-de Haas (EdH) effect [1] is a AC mechanical torque arising from a time rate of change of net magnetization, and represents the intrinsic relationship between magnetism and mechanical angular momentum. Nanofabrication of torque sensing devices is opening new avenues for exploration and applications of the EdH effect. The scale-up of resonance frequencies with continued...
Studies of exchange coupling at interfaces in permalloy/cobalt oxide bilayer microdisks are made possible by measurements of a full AC magnetic torque vector [1]. Magnetic cross-product torque involves a linear combination of perpendicular moment and magnetic susceptibility, yielding the rotational magnetic anisotropy or stiffness of the spin texture in response to torque. Single-axis torque...
The quantum dot cellular automaton (QCA) is a device that uses the interaction between confined electrons in aligned cells to transfer and process information. In QCA architecture, two antipodal arrangements of two electrons confined in square shaped cell are defined as digital “0” and “1”. QCA requires no electrical current for its operation therefore, extremely low power computing can be...
Since the magnetic skyrmion is a topologically protected particle-like domain in the ferromagnetic film, it can survive under thermal agitations and shows Brownian motion. The skyrmion system can be an ideal platform to design unconventional computers like stochastic/Brownian computers. Therefore, investigation of the Brownian motion of the magnetic skyrmion is now the subject of scientific...
High-finesse optical nanocavities coupled with nanomechanical torque sensors have enabled highly sensitive and broadband readout of magnetic torques, from timescales involving quasi-static hysteresis response to radio-frequency magnetic susceptibility [1-3]. The extension of torque magnetometry to higher mechanical frequencies will grant further access to spin dynamics, including mechanical...
Asymmetric charge transport at the interface of two materials with dissimilar electrical properties, such as metal/semiconductor and p-n junctions, is the fundamental feature behind modern diode and transistor technology. Spin pumping from a ferromagnet into an adjacent non-magnetic material is a powerful technique to generate pure-spin-currents, wherein spin transport is unaccompanied by net...
Hybridization of disparate physical systems is a key area of research in harnessing quantum technologies. Exploiting hybridized states can mitigate perturbative effects of reading out quantum states or even enable new devices based on new material properties associated with hybrid quasiparticle excitations. In the area of magnetism a particularly prominent area of progress is the exploration...
