A. W. Tsen

• Office: RAC1 2113, 200 University Ave W, Waterloo, ON N2L 3G1

• Email: awtsen@uwaterloo.ca

• Phone: 519-888-4567 ext. 30375

I am an Associate Professor at the University of Waterloo in the Department of Chemistry and Institute for Quantum Computing. My group focuses on the study of various two-dimensional quantum materials. We use state-of-the-art sample preparation and heterostructure assembly techniques together with magnetotransport and optoelectronic probes.  

I am fortunate to work with the following people: Fangchu Chen (postdoc), Meixin Cheng (postdoc), Yonas Eshete (postdoc), Bowen Yang (postdoc), Xianfan Nie (PhD), Sarah Wang (admin). Alumni: Prof. Hyun Ho Kim (postdoc), Prof. Daozhi Shen (postdoc), Dr. Archana Tiwari (PhD), Dr. Tarun Patel (PhD), Dr. Shazhou Zhong (PhD), Tina Dekker (MSc), Anton Lutsenko (MSc), Fangzhou Yin (BS), Daniel McHaffie (BS), Ivana Rilak (BS), Shaun Froude-Powers (BS), Ashley Cavanagh (BS), Xiaotao Ma (BS), Angela Zhang (high school).

We have openings for postdocs and graduate students. Please send me an email if interested.

We have recently (pre-)published the following papers (see Google Scholar for earlier works):

2024

• "Gate-tunable multiband van der Waals photodetector and polarization sensor," D. Shen, H. Yang, T. Patel, D. A. Rhodes, T. Timusk, Y. N. Zhou, N. Y. Kim, A. W. Tsen, ACS Nano (2024).

2023

• News & Views: "Stress testing the bulk photovoltaic effect," T. Patel, A. W. Tsen. Nature Nanotechnology 18, 3-4 (2023).

• "Magnetic anisotropy reversal driven by structural symmetry-breaking in monolayer α-RuCl3," B. Yang, Y. M. Goh, S. H. Sung, G. Ye, S. Biswas, D. A. S. Kaib, R. Dhakal, S. Yan, C. Li, S. Jiang, F. Chen, H. Lei, R. He, R. Valenti, S. M. Winter, R. Hovden, A. W. Tsen. Nature Materials 22, 50-57 (2023). News & Views: "Structural Tweaking of 2D Quantum Magnetism," H. Miao, G. B. Halasz. Nature Materials 22, 8-9 (2023).

2022

• "Persistent photogenerated state attained by femtosecond laser irradiation of thin Td-MoTe2," M. Cheng, S. Zhong, N. Rivas, T. Dekker, A. A. Petruk, P. Gicala, K. Pichugin, F. Chen, X. Luo, Y. P. Sun, A. W. Tsen, G. Sciaini, J. Phys. Chem. C 126, 13840-13846 (2022).

• "Semiconductor nanowire metamaterial for broadband near-unity absorption," B. Tekcan, B. v. Kasteren, S. V. Grayli, D. Shen, M. C. Tam, D. Ban, Z. Wasilewski, A. W. Tsen, M. E. Reimer, Scientific Reports 12, 9663 (2022).

• "The magnetic genome of two-dimensional van der Waals materials," Q. H. Wang et al., ACS Nano 16, 6960-7079 (2022).

• "High-performance mid-IR to deep-UV van der Waals photodetectors capable of local spectroscopy at room temperature," D. Shen, H. Yang, C. Spudat, T. Patel. S. Zhong, F. Chen, J. Yan, X. Luo, M. Cheng, G. Sciaini, Y. P. Sun, D. A. Rhodes, T. Timusk, Y. N. Zhou, N. Y. Kim, A. W. Tsen, Nano Letters 22, 3425-3432 (2022).

• "Photoinduced interlayer dynamics in Td-MoTe2: a broadband pump-probe study," M. Cheng, S. Zhong, N. Rivas, T. Dekker, A. A. Petruk, P. Gicala, K. Pichugin, F. Chen, X. Luo, Y. P. Sun, A. W. Tsen, G. Sciaini, Applied Physics Letters 120, 123102 (2022).

• "Observation and manipulation of a phase separated state in a charge density wave material," S. M. Walker, T. Patel, J. Okamoto, D. Langenberg, E. A. Bergeron, J. Gao, X. Luo, W. Lu, Y. P Sun, A. W. Tsen, J. Baugh, Nano Letters 22, 1929-1936 (2022).

2021

• "Infrared imaging of samples in ultra high pressure diamond anvil cells," T. Patel, A. Drozdov, V. S. Minkov, M. I. Eremets, E. J. Nicol, J. P. Carbotte, T. Timusk, A. W. Tsen, Journal of Applied Physics 130,173101 (2021).

• "Structural monoclinicity and its coupling to layered magnetism in few-layer CrI3," X. Guo, W. Jin, Z. Ye, G. Ye, H. Xie, B. Yang, H. H. Kim, S. Yan, Y. Fu, S. Tian, H. Lei, A. W. Tsen, K. Sun, J. A. Yan, R. He, L. Zhao, ACS Nano 15, 10444-10450 (2021).

• "Giant c-axis nonlinear anomalous Hall effect in Td-MoTe2 and WTe2," A. Tiwari, F. Chen, S. Zhong, E. Drueke, J. Koo, A. Kaczmarek, C. Xiao, J. Gao, X. Luo, Q. Niu, Y. P. Sun, B. Yan, L. Zhao, A. W. Tsen, Nature Communications 12, 2049 (2021).

• "Quantum engineering with hybrid magnonics systems and materials," D. D. Awschalom et al., IEEE Transactions on Quantum Engineering (2021). 

• "Roadmap on quantum nanotechnologies,"  A. Laucht et al., Nanotechnology 32, 162003 (2021).

2020

• "Photocurrent imaging of multi-memristive charge density wave switching in two-dimensional 1T-TaS2," T. Patel, J. Okamoto, T. Dekker, B. Yang, J. Gao, X. Luo, W. Lu, Y. P. Sun, A. W. Tsen, Nano Letters 20, 7200-7206 (2020).

• "Tunable layered-magnetism-assisted magneto-Raman effect in a two-dimensional magnet CrI3," W. Jin, Z. Ye, X. Luo, B. Yang, G. Ye, F. Yin, H. H. Kim, L. Rojas, S. Tian, Y. Fu, S. Yan, H. Lei, K. Sun, A. W. Tsen, R. He, L. Zhao, Proceedings of the National Academy of Sciences 117, 24664-24669 (2020).

• "Observation of the polaronic character of excitons in a two-dimensional semiconducting magnet CrI3," W. Jin, H. H. Kim, Z. Ye, G. Ye, L. Rojas, X. Luo, B. Yang, F. Yin, J. Horng, S. Tian, Y. Fu, G. Xu, H. Deng, H. Lei,  A. W. Tsen, K. Sun, R. He, L. Zhao, Nature Communications 11, 4780 (2020).

• "Magnetic field-induced quantum phase transitions in a van der Waals magnet," S. Li, Z. Ye, X. Luo, G. Ye, H. H. Kim, B. Yang, S. Tian, C. Li, H. Lei, A. W. Tsen, K. Sun, R. He, L. Zhao, Physical Review X 10, 011075 (2020). Highlight.

• "Magneto-memristive switching in a 2D layer antiferromagnet," H. H. Kim, S. Jiang, B. Yang, S. Zhong, S. Tian, C. Li, H. Lei, J. Shan, K. F. Mak, A. W Tsen, Advanced Materials 32, 1905433 (2020). Inside front cover.

2019

• "Generation and detection of coherent longitudinal acoustic waves in ultrathin 1T'-MoTe2," N. Rivas, S. Zhong, T. Dekker, M. Cheng, P. Gicala, F. Chen, X. Luo, Y. P. Sun, A. A. Petruk, K. Pichugin, A. W. Tsen, G. Sciaini. Applied Physics Letters 115, 223103 (2019). 

• "Tailored tunnel magnetoresistance response in three ultrathin chromium trihalides," H. H. Kim, B. Yang, S. Tian , C. Li , G.-X. Miao, H. Lei, A. W. Tsen, Nano Letters 19, 5739-5745 (2019).

• "Evolution of interlayer and intralayer magnetism in three atomically thin chromium trihalides," H. H. Kim, B. Yang, S. Li, S. Jiang, C. Jin, Z. Tao, G. Nichols, F. Sfigakis, S. Zhong, C. Li, S. Tian, D. G. Cory, G.-X. Miao, J. Shan, K. F. Mak, H. Lei, K. Sun, L. Zhao, A. W. Tsen, Proceedings of the National Academy of Sciences 116, 11131-11136 (2019).

• "Atomic and electronic reconstruction at the van der Waals interface in twisted bilayer graphene," H. Yoo, R. Engelke, S. Carr, S. Fang, K. Zhang, P. Cazeaux, S. H. Sung, R. Hovden, A. W. Tsen, T. Taniguchi, K. Watanabe, G.-C. Yi, M. Kim, M. Luskin, E. B. Tadmor, E. Kaxiras, P. Kim, Nature Materials 18, 448-453 (2019).

2018

• "Raman fingerprint of two terahertz spin wave branches in a two-dimensional honeycomb Ising ferromagnet," W. Jin, H. H. Kim, Z. Ye, S. Li, P. Rezaie, F. Diaz, S. Siddiq, E. Wauer, B. Yang, C. Li, S. Tian, K. Sun, H. Lei, A. W. Tsen, L. Zhao, R. He, Nature Communications 9, 5122 (2018).

• "One million percent tunnel magnetoresistance in a magnetic van der Waals heterostructure," H. H. Kim, B. Yang, T. Patel, F. Sfigakis, C. Li, S. Tian, H. Lei, A. W. Tsen, Nano Letters 18, 4885-4890 (2018).

• "Origin of magnetoresistance suppression in thin γ-MoTe2," S. Zhong, A. Tiwari, G. Nichols, F. Chen, X. Luo, Y. P. Sun, A. W. Tsen, Physical Review B 97, 241409(R) (2018). 

• "Tuning Ising superconductivity with layer and spin-orbit coupling in two-dimensional transition-metal dichalcogenides," S. C. de la Barrera, M. R. Sinko, D. P. Gopalan, N. Sivadas, K. L. Seyler, K. Watanabe, T. Taniguchi, A. W. Tsen, X. Xu, D. Xiao, B. M. Hunt, Nature Communications 9, 1427 (2018).

• "Dimensionality-driven orthorhombic MoTe2 at room temperature," R. He, S. Zhong, H. H. Kim, G. Ye, Z. Ye, L. Winford, D. McHaffie, I. Rilak, F. Chen, X. Luo, Y. P. Sun, A. W. Tsen, Physical Review B 97, 041410(R) (2018). 

• "Infrared nanoimaging of the metal-insulator transition in the charge-density-wave van der Waals material 1T-TaS2," A. J. Frenzel, A. S. McLeod, D. Z. Wang, Y. Liu, W. J. Lu, G. Ni, A. W. Tsen, Y. P. Sun, A. N. Pasupathy, D. N. Basov, Physical Review B 97, 035111 (2018).

We use the following major equipment for our research:

Our work is made possible by support from: University of Waterloo; Industry Canada; National Sciences and Engineering Research Council of Canada; Canada First Research Excellence Fund; National Research Foundation of Korea; Ontario Ministry of Research, Innovation, and Science; US Army Research Office; Killam Program.