Electrical Néel-Order Switching in Magnetron-Sputtered CuMnAs Thin Films

Abstract

Antiferromagnetic materials as active components in spintronic devices promise insensitivity against external magnetic fields, the absence of own magnetic stray fields, and ultrafast dynamics at the picosecond time scale. Materials with certain crystal-symmetry show an intrinsic Néel-order spin-orbit torque that can efficiently switch the magnetic order of an antiferromagnet. The tetragonal variant of CuMnAs was shown to be electrically switchable by this intrinsic spin-orbit effect and its use in memory cells with memristive properties has been recently demonstrated for highquality films grown with molecular beam epitaxy. Here, we demonstrate that the magnetic order of magnetron-sputtered CuMnAs films can also be manipulated by electrical current pulses. The switching efficiency and relaxation as a function of temperature, current density, and pulse width can be described by a thermal-activation model. Our findings demonstrate that CuMnAs can be fabricated with an industry-compatible deposition technique, which will accelerate the development cycle of devices based on this remarkable material. arXiv:1903.12387v2 [cond-mat.mtrl-sci]

Resistive contribution in electrical-switching experiments with antiferromagnets

“…1(a The experimental procedure for the electrical experiments is similar to our experiment on Néel-order switching in CuMnAs, see Ref. [14]. We apply n bursts of current pulses to our structure in one of two orthogonal directions x and y [cf.…”

Scaling the electrical current switching of exchange bias in fully epitaxial antiferromagnet/ferromagnet bilayers

“…Recently, antiferromagnetically coupled materials, such as ferrimagnets, synthetic antiferromagnets (AFMs), and AFMs, have attracted significant attention due to their promising potential in spintronic applications because of several properties, such as the absence of stray magnetic fields, terahertz spin dynamics, and stability against external perturbations [5][6][7] . The electrical current switching of the AFM Néel vector has been demonstrated for several AFM materials, such as CuMnAs 8,9 , Mn 2 Au 10,11 , NiO [12][13][14] , and Fe 2 O 3 15 , with electrical current densities on the order of 10 7 -10 8 A/cm 2 , and recently switching with the order of 10 6 A/cm 2 has been realized on noncollinear AFM of Mn 3 GaN 16 and Mn 3 Sn 17 . In addition, the electrical current switching of ferrimagnets has been demonstrated.…”

Low-energy switching of antiferromagnetic CuMnAs/GaP using sub-10 nanosecond current pulses

“…Further work is required to establish the role of the magnetic anisotropy in determining the stability of the switched state. With the same medium showing both a "leaky" memory state that can be tuned by temperature 10 , and a more stable switching behavior that can be controlled by polarity of the pulse 9 , both switching mechanisms can be utilized to perform memory and processing calculations simultaneously. This is the author's peer reviewed, accepted manuscript.…”

“…Writing of magnetic information using spin-polarized currents, via current-induced spin transfer and spin-orbit torques, has been key to the development of magnetic random-access memory (MRAM) technologies 1,2 . Recently, current-induced switching has been predicted and demonstrated in antiferromagnetic (AF) materials, enriching the field of AF spintronics [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] . With the ability to manipulate AF domains electrically, memory-based spintronic applications can be developed that utilize the terahertz dynamics 8 and multilevel response 7 of the AF order, while also producing no stray magnetic fields and being insensitive to external fields.…”