Padraic Shafer

Education

Professional Experience

2019 – Present
Program Lead
Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA

2012 – Present
Staff Research Scientist
Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA

2009 – 2012
Postdoctoral Research Fellow
Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA

2004 – 2009
Graduate Student Researcher
Department of Materials Science and Engineering – NSF Center of Integrated Nanomechanical Systems, University of California, Berkeley, CA

2002 – 2004
Process Integration Engineer
Logic & Embedded-RAM Alliance for Development, IBM Microelectronics, East Fishkill, NY

1999 – 2002
Process Development Engineer
DRAM Development Alliance, IBM Microelectronics, East Fishkill, NY

Padraic studies electronic order at domain walls and thin film interfaces in complex oxides and magnetic metals using a combination of resonant soft x-ray absorption and scattering. He also investigates spin-pumped dynamics in magnetic multilayers using x-ray based ferromagnetic resonance.

C. Klewe, S. Emori, Q. Li, M. Yang, B. A. Gray, H.-M. Jeon, B. M. Howe, Y. Suzuki, Z. Q. Qiu, P. Shafer, E. Arenholz, Experimental realization of linearly polarized X-ray detected ferromagnetic resonance, New J. Phys. 24, 013030 (2022). [doi: 10.1088/1367-2630/ac465f]

S. S. Cheema, N. Shanker, L.-C. Wang, C.-H. Hsu, S.-L. Hsu, Y.-H. Liao, M. San Jose, J. Gomez, W. Li, J.-H. Bae, S. Volkman, D. Kwon, Y. Rho, G. Pinelli, R. Rastogi, D. Pipitone, C. Stull, M. Cook, B. Tyrrell, V. A. Stoica, Z. Zhang, J. W. Freeland, C. J. Tassone, A. Mehta, G. Soheli, D. Thompson, D. I. Suh, W.-T. Koo, K.-J. Nam, D. J. Jung, W.-B. Song, C.-H. Lin, S. Nam, J. Heo, C. P. Grigoropoulos, P. Shafer, P. Fay, R. Ramesh, J. Ciston, S. Datta, M. Mohamed, C. Hu, and S. Salahuddin, Ultrathin ferroic HfO₂-ZrO₂ superlattice gate stack for advanced transistors, Nature 604, 65–71. (2022) [doi: 10.1038/s41586-022-04425-6]

G. A. Pan, D. Ferenc Segedin, H. LaBollita, Q. Song, E. M. Nica, B. H. Goodge, A. T. Pierce, S. Doyle, D. Có́rdova Carrizales, S. Novakov, A. T. N’Diaye, P. Shafer, H. Paik, J. T. Heron, J. A. Mason, A. Yacoby, L. F. Kourkoutis, O. Erten, C. M. Brooks, A. S. Botana, and J. A. Mundy, Superconductivity in a quintuple-layer square-planar nickelate, Nat. Mater. 21, 160–164 (2022). [doi: 10.1038/s41563-021-01142-9]

(+) I-T. Chiu, M.-H. Lee, S. Cheng, S. Zhang, L. Heki, Z. Zhang, Y. Mohtashami, P. N. Lapa, M. Feng , P. Shafer, A. T. N’Diaye, A. Mehta, J. A. Schuller, G. Galli, S. Ramanathan, Y. Zhu, I. K. Schuller, and Y. Takamura, Cation and anion topotactic transformations in cobaltite thin films leading to Ruddlesden-Popper phases, Phys. Rev. Mater. 5, 064416 (2021) [doi: 10.1103/PhysRevMaterials.5.064416]

A. Fernandez, L. Caretta, S. Das, C. Klewe, D. Lou, E. Parsonnet, R. Gao, A. Luo, P. Shafer, and L. W. Martin, Strain-Induced Orbital Contributions to Oxygen Electrocatalysis in Transition-Metal Perovskites, Adv. Energy Mater. 11, 2102175 (2021). [doi: 10.1002/aenm.202102175]

S. Emori, C. Klewe, J.-M. Schmalhorst, J. Krieft, P. Shafer, Y. Lim, D. A. Smith, A. Sapkota, A. Srivastava, C. Mewes, Z. Jiang, B. Khodadadi, H. Elmkharram, J. J. Heremans, E. Arenholz, G. Reiss, T. Mewes, Element-Specific Detection of Sub-Nanosecond Spin-Transfer Torque in a Nanomagnet Ensemble, Nano Lett. 20(11), 7828–7834 (2020). [doi: 10.1021/acs.nanolett.0c01868]

(+) G. N. Kotsonis, P. B. Meisenheimer, L. Miao, J. Roth, B. Wang, P. Shafer, R. Engel-Herbert, N. Alem, J. T. Heron, C. M. Rost, and J-P Maria, Property and cation valence engineering in entropy-stabilized oxide thin films, Phys. Rev. Mater. 4, 100401(R) (2020) [doi: 10.1103/PhysRevMaterials.4.100401]

P. C. Rogge, P. Shafer, G. Fabbris, W. Hu, E. Arenholz, E. Karapetrova, M. P. M. Dean, R. J. Green, and S. J. May, Depth‐Resolved Modulation of Metal–Oxygen Hybridization and Orbital Polarization across Correlated Oxide Interfaces, Adv. Mater. 31, 1902364 (2019). [doi: 10.1002/adma.201902364]

Q. Li, M. Yang, C. Klewe, P. Shafer, A. T. N’Diaye, D. Hou, T. Y. Wang, N. Gao, E. Saitoh, C. Hwang, R. J. Hicken, J. Li, E. Arenholz, and Z. Q. Qiu, Coherent ac spin current transmission across an antiferromagnetic CoO insulator, Nature Commun. 10, 5265 (2019). [doi: 10.1038/s41467-019-13280-5]

(+) S. Middey, D. Meyers, R. K. Patel, X. Liu, M. Kareev, Shafer, J.-W. Kim, P. J. Ryan, and J. Chakhalian, Phase engineering of rare earth nickelates by digital synthesis, Appl. Phys. Lett. 113, 081602 (2018). [doi: 10.1063/1.5045756]

P. Shafer*, P. García-Fernández*, P. Aguado-Puente, A. R. Damodaran, A. K. Yadav, C. T. Nelson, S.-L. Hsu, J. Wojdeł, J. Íñiguez, L. W. Martin, E. Arenholz, J. Junquera, and R. Ramesh, Emergent chirality in polar vortex superlattices, Proc. Natl. Acad. Sci. 115(5), 915–920 (2018). [doi: 10.1073/pnas.1711652115]

(+) J. Li, L. R. Shelford, P. Shafer, A. Tan, J. X. Deng, P. S. Keatley, C. Hwang, E. Arenholz, G. van der Laan, R. J. Hicken, and Z. Q. Qiu, Direct detection of pure spin-current by x-ray pump-probe measurements, Phys. Rev. Lett. 117, 076602 (2016). [doi: 10.1103/PhysRevLett.117.076602]

J. He*, P. Shafer*, T. R. Mion*, V. T. Tra, Q. He, J. T. Kong, Y.-D. Chuang, W. L. Yang, M. J. Graf, J.-Y. Lin, Y.-H. Chu, E. Arenholz, and R.-H. He, Observation of a three-dimensional quasi-long-range electronic supermodulation in YBa₂Cu₃O_7−x/La_0.7Ca_0.3MnO₃ heterostructures, Nat. Commun. 7, 10852 (2016). [doi: 10.1038/ncomms10852]

Y. Cao, X. Liu, P. Shafer, S. Middey, D. Meyers, M. Kareev, Z. Zhong, J.W. Kim, P. J. Ryan, E. Arenholz, and J. Chakhalian, Anomalous orbital structure in a spinel–perovskite interface, npj Quantum Materials 1, 16009 (2016). [doi: 10.1038/npjquantmats.2016.9]

*These authors contributed equally.

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