Preprints

Flux trapping in NbTiN strips and structures

Ruiheng Bai, Aliakbar Sepehri, Yen-Lee Loh, Anne-Marie Valente-Feliciano, Anna Herr, Quentin Herr, Katja C. Nowack

Scaling NbTiN-based ac-powered Josephson digital to 400M devices/cm2

Anna Herr, Quentin Herr, Steve Brebels, Min-Soo Kim, Ankit Pokhrel, Blake Hodges, Trent Josephsen, Sabine ONeal, Ruiheng Bai, Katja Nowack, Anne-Marie Valente-Feliciano, Zsolt Tökei

arXiv:2303.16792

Reconstruction of current densities from magnetic images by Bayesian Inference

Colin B. Clement, James P. Sethna, Katja C. Nowack

arXiv:1910.12929

Publications

2026

Visualizing the breakdown of the quantum anomalous Hall effect
G. M. Ferguson, Run Xiao, Anthony R. Richardella, Austin Kaczmarek, Nitin Samarth, Katja C. Nowack

PNAS (accepted, 2026).
arXiv:2503.02633

Advancements in NbTiN based circuits for Superconducting Digital Logic
A Pokhrel, B Huet, B Hodges, S Ibrahim, R Bai, S Brebels, T Josephsen, D Buseyne, G Delie, D Vangoidsenhoven, A Elshaer, R Tiwari, DP Lozano, SK Sarkar, L Zhang, S Deckers, H Malavipathirana, JG Pinzon, P Koufalis, R Mishra, C Li, S O'Neal, K Nowack, MJ Van Bael, AM Valente-Feliciano, M Perumkunnil, Z Tőkei

2025 IEEE International Electron Devices Meeting (2025).
arXiv:2410.01940

Unconventional polaronic ground state in superconducting LiTi2O4
Zubia Hasan, Grace A. Pan, Harrison LaBollita, Austin Kaczmarek, Suk Hyun Sung, Shekhar Sharma, Purnima P. Balakrishnan, Edward Mercer, Vivek Bhartiya, Alpha T. N’Diaye, Zaher Salman, Thomas Prokscha, Andreas Suter, Alexander J. Grutter, Mirian Garcia-Fernandez, Ke-Jin Zhou, Jonathan Pelliciari, Valentina Bisogni, Ismail El Baggari, Darrell G. Schlom, Matthew R. Barone, Charles M. Brooks, Katja C. Nowack, Antia S. Botana, Brendan D. Faeth, Alberto de la Torre, Julia A. Mundy

Nat. Comm. 17, 1303 (2026).

2025

Signatures of quantum spin liquid state and unconventional transport in thin film TbInO3
Johanna Nordlander, Margaret A. Anderson, Tony Chiang, Austin Kaczmarek, Nabaraj Pokhrel, Kuntal Talit, Spencer Doyle, Edward Mercer, Christian Tzschaschel, Jun-Ho Son, Hesham El-Sherif, Charles M. Brooks, Eun-Ah Kim, Alberto de la Torre, Ismail El Baggari, Elizabeth A. Nowadnick, Katja C. Nowack, John T. Heron, Julia A. Mundy

Nat. Comm. 16, 9469 (2025).

Direct Comparison of Magnetic Penetration Depth in Kagome Superconductors AV3Sb5 (A = Cs, K, Rb)
Austin Kaczmarek, Andrea Capa Salinas, Stephen D. Wilson, Katja C. Nowack

Phys. Rev. Mat. 9, 074802 (2025).
arXiv:2412.19919

Imaging signatures of edge currents in a magnetic topological insulator
G. M. Ferguson, Run Xiao, Anthony R. Richardella, Austin Kaczmarek, Nitin Samarth, Katja C. Nowack

Phys. Rev. B 112, 075414 (2025).
arXiv:2501.11666

Direct Imaging of Transition-Edge Sensors With Scanning SQUID Microscopy
Samantha Walker, Austin Kaczmarek, Jason Austermann, Douglas Bennett, Shannon M. Duff, Johannes Hubmayr, Ben Keller, Kelsey Morgan, Colin C. Murphy, Daniel Swetz, Joel Ullom, Michael D. Niemack, Katja C. Nowack

IEEE Transactions on Applied Superconductivity (2024).
arXiv:2410.01940

2024

Local magnetic response of superconducting Sr2RuO4 thin films
G. M. Ferguson, Hari P. Nair, Nathaniel J. Schreiber, Ludi Miao, Kyle M. Shen, Darrell G. Schlom, Katja C. Nowack

Phys. Rev. B 110, 144510 (2024).
arxiv:2403.17152

2024 Roadmap on Magnetic Microscopy Techniques and Their Applications in Materials Science
D. V. Christensen, U. Staub, T. R. Devidas, B. Kalisky, K. C. Nowack, J.L. Webb, U.L. Andersen, A. Huck, D. A. Broadway, K. Wagner, P. Maletinsky, T. van der Sar, C. R. Du, A. Yacoby, D. Collomb, S. Bending, A. Oral, H. J. Hug, A.-O. Mandru, V. Neu, H. W. Schumacher, S. Sievers, H. Saito, A.A. Khajetoorians, N. Hauptmann, S. Baumann, A. Eichler, C. L. Degen, J. McCord, M. Vogel, M. Fiebig, P. Fischer, A. Hierro-Rodriguez, S. Finizio, S. S. Dhesi, C. Donnelly, Felix Büttner, O. Kfir, W. Hu, S. Zayko, S. Eisebitt, B. Pfau, R. Frömter, M. Kläui, F. S. Yasin, B. J. McMorran, S. Seki, X. Yu, A. Lubk, D. Wolf, N. Pryds, D. Makarov, M. Poggio

J. Phys. Materials 7, 032501 (2024).
arxiv:2401.04793

2023

Direct visualization of electronic transport in a quantum anomalous Hall insulator
G. M. Ferguson, Run Xiao, Anthony R. Richardella, David Low, Nitin Samarth, Katja C. Nowack

Nat. Mat. 22, 1100 (2023).
arXiv:2112.13122

Current-induced switching of thin film alpha-Fe2O3 devices imaged using a scanning single-spin microscope
Qiaochu Guo, Anthony D'Addario, Yang Cheng, Jeremy Kline, Isaiah Gray, Hil Fung Harry Cheung, Fengyuan Yang, Katja C. Nowack*, and Gregory D. Fuchs* *Corresponding author.

Phys. Rev. Mat. 7, 064402 (2023).
arxiv:2210.06233

Superfluid response of an atomically thin, gate-tuned van der Waals superconductor
Alexander Jarjour, G.M. Ferguson, Brian T. Schaefer, Menyoung Lee, Yen Lee Loh, Nandini Trivedi, Katja C. Nowack

Nat. Comm. 14, 2055 (2023).
arXiv:2209.11800

2021

Scanning SQUID microscopy in a cryogen-free dilution refrigerator
D. Low, G. M. Ferguson, Alexander Jarjour, Brian T. Schaefer, Maja D. Bachmann, Philip J. W. Moll, Katja C. Nowack

Review of Scientific Instruments 92, 083704 (2021).
arXiv:2102.09588
Link to CAD file

Electrically tunable and reversible magnetoelectric coupling in strained bilayer graphene
B. T. Schaefer, K. C. Nowack

Phys. Rev. B 103, 224426 (2021).
arXiv:2103.04124

Patternable Mesoporous Thin Film Quantum Materials via Block Copolymer Self-Assembly: An Emergent Technology?
4. F. Yu, R. P. Thedford, K. R. Hedderick, G. Freychet, M. Zhernenkov, L. A. Estroff, K. C. Nowack, S. M. Gruner, U. B. Wiesner

ACS Applied Materials & Interfaces 13,34732 (2021).

Superconducting Quantum Metamaterials from High Pressure Melt Infiltration of Metals into Block Copolymer Double Gyroid Derived Ceramic Templates
R. Paxton Thedford,Peter A. Beaucage,Ethan M. Susca,Corson A. Chao,Katja C. Nowack,Robert B. Van Dover,Sol M. Gruner,Ulrich Wiesner

Advanced Functional Materials 31, 2100469 (2021).

2020

Magnetic field detection limits for ultraclean graphene Hall sensors
Brian T. Schaefer, Lei Wang, Alexander Jarjour, Kenji Watanabe, Takashi Taniguchi, Paul L. McEuen, Katja C. Nowack

Nature Communications 11, 4163 (2020).

s41467-020-18007-5.pdf

2019

Spin Seebeck imaging of spin-torque switching in antiferromagnetic Pt/NiO/Pt heterostructures
Isaiah Gray, Takahiro Moriyama, Nikhil Sivadas, Gregory M. Stiehl, John T. Heron, Ryan Need, Brian J. Kirby, David H. Low, Katja C. Nowack, Darrell G. Schlom, Daniel C. Ralph, Teruo Ono, Gregory D. Fuchs

Phys. Rev. X 9, 041016 (2019).
arXiv:1810.03997

Spatial control of heavy-fermion superconductivity in CeIrIn5
Maja D. Bachmann*, G. M. Ferguson*, Florian Theuss, Tobias Meng, Carsten Putzke, Toni Helm, K. R. Shirer, You-Sheng Li, K. A. Modic, Michael Nicklas, Markus Koenig, D. Low, Sayak Ghosh, Andrew P. Mackenzie, Frank Arnold, Elena Hassinger, Ross D. McDonald, Laurel E. Winter, Eric D. Bauer, Filip Ronning, B. J. Ramshaw, Katja C. Nowack**, Philip J. W. Moll** *These authors contributed equally. **These authors contributed equally/ Corresponding author.

Science 366, 221 (2019). DOI: 10.1126/science.aao6640
arXiv:1807.05079

Thickness dependence of superconductivity in ultrathin NbS2
Rusen Yan, Guru Khalsa, Brian T Schaefer, Alexander Jarjour, Sergei Rouvimov, Katja C Nowack, Huili G Xing, and Debdeep Jena

Applied Physics Express 12, 023008 (2019).
arXiv:1803.06097

2016

Variation in superconducting transition temperature due to tetragonal domains in two-dimensionally doped SrTiO3
H. Noad, E. M. Spanton, K. C. Nowack, H. Inoue, M. Kim, T. A. Merz, C. Bell, Y. Hikita, R. Xu, W. Liu, A. Vailionis, H. Y. Hwang, K. A. Moler

Physical Review B 94, 174516 (2016).

PhysRevB.94.174516.pdf

Publications from previous collaborations

2014

Images of edge current in InAs/GaSb quantum wells
Eric M. Spanton, K. C. Nowack, L. Du, R.-R. Du and K. A. Moler

Physical Review Letters 113, 026804 (2014).

DOI: http://dx.doi.org/10.1103/PhysRevLett.113.026804

2013

Locally enhanced conductivity due to tetragonal domain structure in LaAlO3/SrTiO3 heterointerfaces
B. Kalisky, E. M. Spanton, H. Noad, J. R. Kirtley, K. C. Nowack, C. Bell, H. K. Sato, Y. Xie, Y. Hikita, C. Woltmann, G. Pfanzelt, R. Jany, H. Y. Hwang, J. Mannhart and K. A. Moler

Nature Materials 12, 1091-1095 (2013). doi:10.1038/nmat3753

Current flows along the edge in the QSH regime

Imaging currents in HgTe quantum wells in the quantum spin Hall regime
K. C. Nowack, E. M. Spanton, M. Baenninger, M. Koenig, J. R. Kirtley, B. Kalisky, C. Ames, Philipp Leubner, C. Bruene, H. Buhmann, L. W. Molenkamp, D. Goldhaber-Gordon and K. A. Moler

Nature Materials 12, 787-791 (2013). doi:10.1038/nmat3682

Nuclear spin effects in semiconductor quantum dots
E. A. Chekhovich, M. N. Makhonin, A. I. Tartakovskii, A.Yacoby, H. Bluhm, K. C. Nowack and L. M. K. Vandersypen

review article, Nature Materials 12, 494-504 (2013).

Simultaneous Spin-Charge Relaxation in Double Quantum Dots
V. Srinivasa, K. C. Nowack, M. Shafiei, L. M. K. Vandersypen, J. Taylor

Physical Review Letters 110 196803 (2013). DOI: http://dx.doi.org/10.1103/PhysRevLett.110.196803

Resolving Spin-Orbit and Hyperfine Mediated Electric Dipole Spin Resonance in a Quantum Dot
M. Shafiei, K. C. Nowack, C. Reichl, W. Wegscheider and L. M. K. Vandersypen

Physical Review Letters 110 107601 (2013). DOI: http://dx.doi.org/10.1103/PhysRevLett.110.107601

2012

Gate-tuned superfluid density at the superconducting LaAlO3/SrTiO3 interface
J. A. Bert, K. C. Nowack, B. Kalisky, H. Noad, J. R. Kirtley, C. Bell, H. K. Sato, M. Hosoda, Y. Hikita, H. Y. Hwang and K. A. Moler

Physical Review B 86, 060503(R) (2012). doi: 10.1103/PhysRevB.86.060503

2011

Single-Shot Correlations and Two-Qubit Gate of Solid-State Spins
K. C. Nowack, M. Shafiei, M. Laforest, G. E. D. K. Prawiroatmodjo, L. R. Schreiber, C. Reichl, W. Wegscheider and L. M. K. Vandersypen

Science 333 1269 (2011). DOI: 10.1126/science.1209524

2009

Electrical Manipulation and Detection of Single Electron Spins in Quantum Dots
Katja Nowack

Thesis. ISBN: 978-90-8593-063-1.

PDF

Locking electron spins into resonance by electron-nuclear feedback
I. T. Vink, K. C. Nowack, F. H. L. Koppens, J. Danon, Yu. V. Nazarov and L. M. K. Vandersypen

Nature Physics 5 764 (2009). doi:10.1038/nphys1366

Multiple nuclear polarization states in a double quantum dot
J. Danon, I. T. Vink, F. H. L. Koppens, K. C. Nowack, L. M. K. Vandersypen and Yu. V. Nazarov

Physical Review Letters 103 046601 (2009). DOI: http://dx.doi.org/10.1103/PhysRevLett.103.046601

2008

Spin Echo of a Single Electron Spin in a Quantum Dot
F. H. L. Koppens, K. C. Nowack and L. M. K. Vandersypen

Physical Review Letters 100 236802 (2008). DOI: http://dx.doi.org/10.1103/PhysRevLett.100.236802

2007

Coherent Control of a Single Electron Spin with Electric Fields
K. C. Nowack, F. H. L. Koppens, Yu. V. Nazarov, and L. M. K. Vandersypen

Science 318 1430 (2007). DOI:10.1126/science.1148092

Universal Phase Shift and Nonexponential Decay of Driven Single-Spin Oscillations
F. H. L. Koppens, D. Klauser, W. A. Coish, K. C. Nowack, L. P. Kouwenhoven, D. Loss, and L. M. K. Vandersypen

Physical Review Letters 99 106803 (2007). DOI: http://dx.doi.org/10.1103/PhysRevLett.99.106803

Detection of single electron spin resonance in a double quantum dot
F. H. L. Koppens, C. Buizert, I. T. Vink, K. C. Nowack, T. Meunier, L. P. Kouwenhoven, and L. M. K. Vandersypen

Journal of Applied Physics 101 081706 (2007). http://dx.doi.org/10.1063/1.2722734. See also http://proceedings.aip.org/proceedings/confproceed/893.jsp.

2006

Driven coherent oscillations of a single electron spin in a quantum dot
F. H. L. Koppens, C. Buizert, K. J. Tielrooij, I. T. Vink, K. C. Nowack, T. Meunier, L. P. Kouwenhoven, and L. M. K. Vandersypen

Nature 442 766 (2006). doi:10.1038/nature05065