Publications [Google Scholar]

2025

X.-W. Lu and C.-F. Pai*, "Direct linking of interfacial and interlayer chiral exchange coupling observed through interface tuning," Applied Physics Letters 127, 082404 (2025).

T.-Y. Hung, J.-Y. Hsieh, W.-B. Liao, C.-Y. Lin, C.-Y. Lo, S.-C. Chiu, Y.-C. Hsin, J.-H. Wei, and C.-F. Pai*, "High-TMR SHNO-Based Ising Machines for CMOS-Compatible Unconventional Computing," IEEE Electron Device Letters, Early Access (2025).

C.-Y. Lin, T.-C. Huang, T.-C. Hsin, and C.-F. Pai*, "Field-Free Spin–Orbit Torque-Induced Exchange Bias Switching," ACS Applied Electronic Materials 7, 6655 (2025).

T.-C. Huang, K.-Y. Chi, C.-Y. Lin*, C. Yang, M.-Y. Song, C.-Y. Hu, X. Bao, and C.-F. Pai, "Pt-Based Multilayers Toward Energy-Efficient Spin-Orbit Torque Devices," Applied Physics Letters 127, 032405 (2025).

C.-C. Peng, C.-J. Wu, S.-C. Lai, C.-Y. Hu, M.-Y. Song, X. Bao, Y.-M. Lin, and C.-F. Pai*, "Superparamagnetic Nanoparticles vs. Ferromagnetic Nanowires: A Comparative Simulation Study for High-Frequency Inductor Applications," J. Magn. Magn. Mater. 629, 173221 (2025).

Y.-C. Huang, T.-Y. Hung, C.-Y. Lin, J.-H. Han, C.-C. Peng, and C.-F. Pai*, "Characterization of Spin Torque Dynamics in Heterostructures with Interlayer Dzyaloshinskii-Moriya Interactions," ACS Applied Electronic Materials 7, 5721 (2025).

Y.-H. Huang†, X.-W. Lu†, J.-H. Han, C.-C. Peng, and C.-F. Pai*, "Experimental confirmation of Ruderman-Kittel-Kasuya-Yosida-type interlayer Dzyaloshinskii-Moriya interaction across Ru spacers," Physical Review Materials 9, L051401 (2025). (Editor's Suggestion)

C.-Y. Hu, M.-Y. Song, X. Bao, and C.-F. Pai*, "Efficient Magnetization Switching via Orbital-to-Spin Conversion in Cr/W-based Heterostructures," ACS Applied Electronic Materials 7, 4279 (2025).

T.-C. Hsin†, C.-Y. Lin†, P.-C. Wang, C. Yang, and C.-F. Pai*, "All‐Electrical Control of Spin Synapses for Neuromorphic Computing: Bridging Multi‐State Memory with Quantization for Efficient Neural Networks," Advanced Science 2417735 (2025).

2024

Y.-T. Liu, C.-C. Peng, T.-Y. Hung, Y.-H. Huang, and C.-F. Pai*, "Advancing the problem-solving capabilities of Ising machines based on spin Hall nano-oscillators," Physical Review Applied 22, 064009 (2024).

C.-Y. Lin, J.-Y. Hsieh, P.-C. Wang, C.-C. Tsai, and C.-F. Pai*, "Field-free spin-orbit torque devices for logic and neural network applications," APL Machine Learning 2, 046110 (2024).

H.-K. Chang, K.-Y. Chi, Y.-L. Lin, Y.-H. Lai, Y.-L. Huang, C.-F. Pai, and C.-Y. Yang, "Spin–Orbit Torque Booster in an Antiferromagnet via Facilitating a Global Antiferromagnetic Order: A Route toward an Energy-Efficient Memory," ACS Appl. Mater. Interfaces 16, 65037 (2024).

C.-Y. Hu†, W.-D. Chen†, Y.-T. Liu, C.-C. Huang, and C.-F. Pai*, "The Central Role of Tilted Anisotropy for Field-Free Spin-Orbit Torque Switching of Perpendicular Magnetization," NPG Asia Materials 16, 1 (2024).

Y.-H. Huang†, J.-H. Han†, W.-B. Liao, C.-Y. Hu, Y.-T. Liu, and C.-F. Pai*, "Tailoring Interlayer Chiral Exchange by Azimuthal Symmetry Engineering," Nano Letters 24, 649 (2024).

C.-Y. Lin, P.-C. Wang, Y.-H. Huang, W.-B. Liao, M.-Y. Song, X. Bao, and C.-F. Pai*, "Field-free Spin-Orbit Torque Switching via Oscillatory Interlayer Dzyaloshinskii–Moriya Interaction for Advanced Memory Applications," ACS Materials Letters 6, 400 (2024).

T.-C. Huang, W.-H. Wu, M.-T. Wu, C. Chuang, C.-F. Pai, Y.-P. Hsieh, M. Hofmann, "Realizing high-quality interfaces in 2D material spin valves," ACS Materials Letters 6, 94 (2024).

2023

M. Song, G. Chen, K. Chen, K. Chang, I. Wang, Y. Hsin, C.-Y. Lin, E. Ambrosi, W. Khwa, Y. Lu, C.-Y. Hu, S. Yang, S. Li, J. Wei, T. Y. Lee, A. Wang, M. Chang, C.-F. Pai, X. Bao, "High RA Dual-MTJ SOT-MRAM devices for High Speed (10ns) Compute-in-Memory Applications," IEEE International Electron Devices Meeting (IEDM) (2023).

S.-C. Kao†, C.-Y. Lin†, W.-B. Liao, P.-C. Wang, C.-Y. Hu, Y.-H. Huang, Y.-T. Liu, and C.-F. Pai*, "Field-free magnetization switching through modulation of zero-field spin-orbit torque efficacy," APL Materials 11, 111104 (2023).

W.-B. Liao, C.-Y. Lin, T.-Y. Cheng, C.-C. Huang, T.-Y. Chen, and C.-F. Pai*, "Processing effect on spin-orbit torque switching and efficiency characterization in perpendicularly magnetized pillar devices," Physical Review Materials 7, 104409 (2023).

Y.-C. Li†, Y.-H. Huang†, C.-C. Huang, Y.-T. Liu, and C.-F. Pai*, "Field-Free Switching in Symmetry-Breaking Multilayers: The Critical Role of Interlayer Chiral Exchange," Physical Review Applied 20, 024032 (2023).

C.-Y. Hu, Y.-F. Chiu, C.-C. Tsai, C.-M. Lee, M.-Y. Song, S.-J. Lin, X. Bao, and C.-F. Pai*, "Interfacial Engineering Strategies for Efficient Spin–Orbit Torque Devices with Pt Alloys," ACS Applied Electronic Materials 5, 968 (2023).

2022

Y.-T. Liu, Y.-H. Huang, C.-C. Huang, Y.-C. Li, C.-L. Cheng, and C.-F. Pai*, "Field-Free Type-x Spin-Orbit Torque Switching by Easy Axis Engineering," Physical Review Applied 18, 034019 (2022). 

Y.-H. Huang, C.-C. Huang, W.-B. Liao, T.-Y. Chen, and C.-F. Pai*, "Growth-dependent Interlayer Chiral Exchange and Field-free Switching," Physical Review Applied 18, 034046 (2022). 

C.-C. Huang, C.-C. Tsai, W.-B. Liao, T.-Y. Chen, and C.-F. Pai*, "Deep learning for spin-orbit torque characterizations with a projected vector field magnet," Physical Review Research 4, 033040 (2022). 

T.-Y. Chen, Y.-C. Hsiao, W.-B. Liao, and C.-F. Pai*, "Tailoring Neuromorphic Switching by CuNx-mediated Orbital Currents," Physical Review Applied 17, 064005 (2022). 

M. X. Guo, C. K. Cheng, Y. C. Liu, C. N. Wu, W. N. Chen, T. Y Chen, C. T. Wu, C. H. Hsu, S. Q. Zhou, C. F. Chang, L. H. Tjeng, S. F. Lee, C. F. Pai, M. Hong, J. Kwo, "Single-crystal epitaxial europium iron garnet films with strain-induced perpendicular magnetic anisotropy: structural, strain, magnetic, and spin transport properties," Physical Review Materials 6, 054412 (2022). 

C.-Y. Hu†, Y.-F. Chiu†, C.-C. Tsai, C.-C. Huang, K.-H. Chen, C.-W. Peng, C.-M. Lee, M.-Y. Song, Y.-L. Huang, S.-J. Lin, and C.-F. Pai*, "Toward 100% Spin-Orbit Torque Efficiency with High Spin-Orbital Hall Conductivity Pt-Cr Alloys," ACS Applied Electronic Materials 4, 1099 (2022). (ACS Editor's Choice) 

2021

Y.-T. Liu†, C.-C. Huang†, K.-H. Chen, Y.-H. Huang, C.-C. Tsai, T.-Y. Chang, C.-F. Pai*, "Anatomy of Type-X Spin-Orbit Torque Switching," Physical Review Applied 16, 024021 (2021).

T.-Y. Chang, C.-L. Cheng, C.-C. Huang, C.-W. Peng, Y.-H. Huang, T.-Y. Chen, Y.-T. Liu, and C.-F. Pai*, "Large Unidirectional Magnetoresistance in Metallic Heterostructures in the Spin Transfer Torque Regime," Physical Review B 104, 024432 (2021).

S.-J. Lin, Y.-L. Huang, MY Song, C.-M. Lee, F. Xue, G.-L. Chen, S.-Y. Yang, Y.-J. Chang, I-J. Wang, Y.-C. Hsin, Y.-H. Su, J.-H. Wei, C.-F. Pai, S. X. Wang, C. H. Diaz, "Challenges toward Low-Power SOT-MRAM," IEEE International Reliability Physics Symposium (IRPS) (2021).

M.-H. Nguyen* and C.-F. Pai*, "Spin-Orbit Torque Characterization in a Nutshell," APL Materials 9, 030902 (2021). (Perspectives on Emerging Materials for Spin-Charge Interconversion)

C.-W. Peng†, W.-B. Liao†, T.-Y. Chen, and C.-F. Pai*, "Efficient Spin-Orbit Torque Generation in Semiconducting WTe2 with Hopping Transport," ACS Appl. Mater. Interfaces 13, 15950 (2021).

2020

W.-B. Liao, T.-Y. Chen, Y.-C. Hsiao, and C.-F. Pai*, "Pulse-width and Temperature Dependence of Memristive Spin-Orbit Torque Switching," Applied Physics Letters 117, 182402 (2020).

C.-Y. Hu and C.-F. Pai*, "Benchmarking of spin-orbit torque switching efficiency in Pt alloys," Advanced Quantum Technologies 3, 2000024 (2020).

Y.-T. Liu, T.-Y. Chen, T.-H. Lo, T.-Y. Tsai, S.-Y. Yang, Y.-J. Chang, J.-H. Wei, and C.-F. Pai*, "Determination of Spin-Orbit Torque Efficiencies in Heterostructures with In-plane Magnetic Anisotropy," Physical Review Applied 13, 044032 (2020).

T.-Y. Chen, W.-B. Liao, T.-Y. Chen, T.-Y. Tsai, C.-W. Peng, and C.-F. Pai*, "Current-induced spin-orbit torque efficiencies in W/Pt/Co/Pt heterostructures," Applied Physics Letters 116, 072405 (2020).

S. Z. Rahaman, I.-J. Wang, D.-Y. Wang, C.-F. Pai, Y.-C. Hsin, S.-Y. Yang, H.-H. Lee, Y.-J. Chang, Y.-C. Kuo, Y.-H. Su, G.-L. Chen, F.-M. Chen, J.-H. Wei, T.-H. Hou,  S.-S. Sheu, C.-I. Wu, and D.-L. Deng, "Size-Dependent Switching Properties of Spin-Orbit Torque MRAM With Manufacturing-Friendly 8-Inch Wafer-Level Uniformity," IEEE Journal of the Electron Devices Society 8, 163 (2020).

T.-H. Lo, Y.-C. Weng, C.-F. Pai, J. G. Lin, "Effect of asymmetric Pt thickness on the inverse spin Hall voltage in Pt/Co/Pt trilayers," AIP Advances 10, 025120 (2020).

T.-Y. Chen, C.-W. Peng, T.-Y. Tsai, W.-B. Liao, C.-T. Wu, H.-W. Yen, and C.-F. Pai*, "Efficient Spin-Orbit Torque Switching with Nonepitaxial Chalcogenide Heterostructures," ACS Appl. Mater. Interfaces 12, 7788 (2020).

2019

N. Murray, W.-B. Liao, T.-C. Wang, L.-J. Chang, L.-Z. Tsai, T.-Y. Tsai, S.-F. Lee, and C.-F. Pai*, "Field-free spin-orbit torque switching through domain wall motion," Physical Review B 100, 104441 (2019).

W.-B. Liao, T.-Y. Chen, Y. Ferrante, S. S. P. Parkin, and C.-F. Pai*, "Current-induced magnetization switching by the high spin Hall conductivity α-W," Physica Status Solidi (RRL) - Rapid Research Letters 13, 1900408 (2019).

T.-C. Chuang, C.-F. Pai, and S.-Y. Huang, “Cr-induced perpendicular magnetic anisotropy and field-free spin-orbit torque switching”, Physical Review Applied 11, 061005 (2019).

2018

T.-Y. Chen†, Y. Ou†, T.-Y Tsai, R. A. Buhrman, and C.-F. Pai*, "Spin-orbit torques acting upon a perpendicularly-magnetized Py layer," APL Materials 6, 121101 (2018).

T.-Y. Chen, H.-I. Chan, W.-B. Liao, and C.-F. Pai*, "Current-induced spin-orbit torque and field-free switching from Mo-based magnetic heterostructures," Physical Review Applied 10, 044038 (2018).

Chi-Feng Pai*, "Switching by Topological Insulators," Nature Materials 17, 755 (2018).

Sk. Z. Rahaman, I.-J. Wang, T.-Y. Chen, C.-F. Pai, D.-Y. Wang, J.-H. Wei, H.-H. Lee, Y.-C. Hsin, Y.-J. Chang, S.-Y. Yang, Y.-C. Kuo, Y.-H. Su, Y.-S. Chen, K.-C. Huang, C.-I Wu, and D.-L. Deng, "Pulse-Width and Temperature Effect on the Switching Behavior of an Etch-Stop-On-MgO-Barrier Spin-Orbit Torque MRAM Cell," IEEE Electron Device Letters 39, 1306 (2018).

T.-Y. Tsai, T.-Y. Chen, C.-T. Wu, H.-I Chan, C.-F. Pai*, "Spin-orbit torque magnetometry by wide-field magneto-optical Kerr effect," Scientific Reports 8, 5613 (2018).

T.-C. Wang, T.-Y. Chen*, C.-T. Wu, H.-W. Yen, and C.-F. Pai*, "Comparative Study on Spin-Orbit Torque Efficiencies from W/ferromagnetic and W/ferrimagnetic Heterostructures," Physical Review Materials 2, 014403 (2018).

2017

T.-Y. Chen, T.-C. Chuang, S.-Y. Huang, H.-W. Yen, and C.-F. Pai*, "Spin-orbit torque from a magnetic heterostructure of high-entropy alloy," Physical Review Applied 8, 044005 (2017).

T.-Y. Chen, C.-T. Wu, H.-W. Yen, and C.-F. Pai*, "Tunable spin-orbit torque in Cu-Ta binary alloy heterostructures," Physical Review B 96, 104434 (2017).

C. O. Avci, A. Quindeau, M. Mann, C.-F. Pai, C. A. Ross, and G. S. D. Beach, "Spin transport in as-grown and annealed thulium iron garnet/platinum bilayers with perpendicular magnetic anisotropy,"  Physical Review B 95, 115428 (2017)

2016

K. Ueda, M. Mann, C.-F. Pai, A. J. Tan, and G. S. D. Beach, "Spin-orbit torques in Ta/TbxCo100-x ferrimagnetic alloy films with bulk perpendicular magnetic anisotropy," Applied Physics Letters 109, 232403 (2016).

C. O. Avci, A. Quindeau, C.-F. Pai, M. Mann, L. Caretta, A. S. Tang, M. C. Onbasli, C. A. Ross, and G. S. D. Beach, "Current-Induced Switching in a Magnetic Insulator," Nature Materials 16, 309 (2016).

Y. Ou, C.-F. Pai, S. Shi, D. C. Ralph, and R. A. Buhrman, "Origin of fieldlike spin-orbit torques in heavy metal/ferromagnet/oxide thin film heterostructures," Physical Review B 94, 140414(R) (2016). (Rapid Communication)

K. Ueda, C.-F. Pai, A. J. Tan, M. Mann, and G. S. D. Beach, "Effect of rare earth metal on the spin-orbit torque in magnetic heterostructures," Applied Physics Letters 108, 232405 (2016).

C.-F. Pai*, M. Mann, A. J. Tan, and G. S. D. Beach, “Determination of Spin Torque Efficiencies in Heterostructures with Perpendicular Magnetic Anisotropy,” Physical Review B 93, 144409 (2016). (Editor's Suggestion)

K. An, X. Ma, C.-F. Pai, J. Yang, K. S. Olsson, J. L. Erskine, D. C. Ralph, R. A. Buhrman, and X. Li, “Current Control of Magnetic Anisotropy via Stress in a Ferromagnetic Metal Waveguide,” Physical Review B 93, 140404(R) (2016). (Rapid Communication / Editor's Suggestion)

Older works

M.-H. Nguyen, C.-F. Pai, K. X. Nguyen, D. A. Muller, D. C. Ralph, and R. A. Buhrman, “Enhancement of the anti-damping spin torque efficacy of the spin Hall effect in Pt by interface modification,” Applied Physics Letters 106, 222402 (2015).

C.-F. Pai†, Y. Ou†, L. H. V.-Leão, D. C. Ralph, and R. A. Buhrman, “Dependence of the Efficiency of Spin Hall Torque on the Transparency of Pt-Ferromagnetic Layer Interfaces,” Physical Review B 92, 064426 (2015). (Editor's Suggestion)

C.-F. Pai, M.-H. Nguyen, C. Belvin, L. H. V.-Leão, D. C. Ralph, and R. A. Buhrman, “Enhancement of perpendicular magnetic anisotropy and transmission of spin-Hall-effect-induced spin currents by a Hf spacer layer in W/Hf/CoFeB/MgO layer structures,” Applied Physics Letters 104, 082407 (2014).

O. J. Lee, L. Q. Liu, C.-F. Pai, Y. Li, H. W. Tseng, P. G. Gowtham, J. Park, D. C. Ralph, and Robert A. Buhrman, “The central role of domain wall depinning for perpendicular magnetization switching driven by spin torque from the spin Hall effect,” Physical Review B 89, 024418 (2014). (Editor's Suggestion)

K. An, D. R. Birt, C.-F. Pai, K. Olsson, D. C. Ralph, R. A. Buhrman, and X. Li, “Control of propagating spin waves via spin transfer torque in a metallic bilayer waveguide,” Physical Review B 89, 140405(R) (2014). (Rapid Communication)

L. Q. Liu, C.-F. Pai, D. C. Ralph, and R. A. Buhrman, “Gate voltage modulation of spin-Hall-torque-driven magnetic switching,” arXiv:1209.0962 (2012).

L. Q. Liu, C.-F. Pai, D. C. Ralph, and R. A. Buhrman, “Magnetic oscillations driven by the spin Hall effect in 3-terminal magnetic tunnel junction devices,” Physical Review Letters 109, 186602 (2012).

C.-F. Pai*, L. Q. Liu, Y. Li, H. W. Tseng, D. C. Ralph, and R. A. Buhrman, “Spin transfer torque devices utilizing the giant spin Hall effect of tungsten,” Applied Physics Letters 101, 124404 (2012).

L. Q. Liu†, C.-F. Pai†, Y. Li, H. W. Tseng, D. C. Ralph, and R. A. Buhrman, “Spin-torque switching with the giant spin Hall effect of tantalum,” Science 336, 555 (2012).

Books

Denny D. Tang and Chi-Feng Pai, Magnetic Memory Technology: Spin-Transfer Torque MRAM and Beyond, Wiley-IEEE Press, 1st Edition (January 7, 2021). 

Patents

"Magnetic structure capable of field-free spin-orbit torque switching and production method and use thereof": US20220376170A1 (November 24, 2022). Inventors: Chi-Feng Pai, Tian-Yue Chen, Wei-Bang Liao.

"Memory device and manufacturing method thereof": US12156479B2 (Granted: November 26, 2024). Inventors: Yen-Lin Huang, Mingyuan Song, Chien-Min Lee, Shy-Jay Lin, Chi-Feng Pai, Chen-Yu Hu, Chao-Chung Huang, Kuan-Hao Chen, Chia-Chin Tsai, Yu-Fang Chiu, Cheng-Wei Peng.

"Circuits and devices based on enhanced spin hall effect for efficient spin transfer torque": US10008248B2 (Granted: June 26, 2018). Inventors: Robert A. Buhrman, Minh-Hai  Nguyen, Chi-Feng Pai, Daniel C. Ralph.

“Electrically gated three-terminal circuits and devices based on spin hall torque effects in magnetic nanostructures apparatus, methods and applications”: US9230626B2 (Granted: January 5, 2016). Inventors: Robert A. Buhrman, Daniel C. Ralph, Chi-Feng Pai, Luqiao Liu.

“Spin hall effect magnetic apparatus, method and applications”: US9105832B2 (Granted: August 11, 2015). Inventors: Robert A. Buhrman, Daniel C. Ralph, Luqiao Liu, Chi-Feng Pai.