Logan Bishop-Van Horn

Logan Bishop-Van Horn

Technical staff scientist @ MIT Lincoln Laboratory

Publications

Articles are in reverse chronological order (most recent first).

You can also find my work on Google Scholar and arXiv.

Vortex motion induced losses in tantalum resonators

Published in Physical Review B, 2026

Tantalum (Ta)-based superconducting circuits have been demonstrated to enable ultrahigh qubit quality factors (Q), motivating a careful study of the microscopic origin of the remaining losses that limit their performance. We have recently shown that the losses in Ta-based resonators are dominated by two-level systems at low microwave powers and millikelvin temperatures. We also observe that some devices exhibit loss that is exponentially activated at a lower temperature inconsistent with the superconducting critical temperature (Tc) of the constituent film. Specifically, dc resistivity measurements show a T𝑐 of over 4 K, while microwave measurements of resonators fabricated from these films show losses that increase exponentially with temperature with an activation energy as low as 0.3 K. Here, we present a comparative study of the structural and thermodynamic properties of Ta-based resonators and identify vortex motion-induced loss as the source of thermally activated microwave loss. Through careful magnetoresistance and x-ray diffraction measurements, we observe that the increased loss occurs for films that are in the clean limit, where the superconducting coherence length (𝜉) is shorter than the mean free path (𝑙). Vortex motion-induced losses are suppressed for films in the dirty limit, which show evidence of structural defects that can pin vortices. We verify this hypothesis by explicitly pinning vortices via patterning, and we find that we can suppress the loss by microfabrication.

Citation: Faranak Bahrami, Matthew P. Bland, Nana Shumiya, Ray D. Chang, Elizabeth Hedrick, Russell A. McLellan, Kevin D. Crowley, Aveek Dutta, Logan Bishop-Van Horn, Yusuke Iguchi, Aswin Kumar Anbalagan, Guangming Cheng, Chen Yang, Nan Yao, Andrew L. Walter, Andi M. Barbour, Sarang Gopalakrishnan, Robert J. Cava, Andrew A. Houck, Nathalie P. de Leon, "Vortex motion induced losses in tantalum resonators", Physical Review B 113, 054505 (2026). https://doi.org/10.1103/4ny9-9n5b

Quantum printing and induced vorticity in superconductors II: Laguerre-Gaussian beam

Published in Physical Review Research, 2025

The challenge of controlling the quantum states of matter via light has been at the forefront of modern research on driven quantum matter. We explore the imprinting effects of structured light on superconductors, demonstrating how the quantum numbers of light—specifically spin angular momentum, orbital angular momentum, and radial order—can be transferred to the superconducting (SC) order parameter and control vortex dynamics. Using Laguerre-Gaussian beams, we show that by tuning the quantum numbers and the amplitude of the electric field, it is possible to manipulate a variety of vortex dynamics, including breathing vortex pairs, braiding vortex pairs, vortex droplets, and swirling two-dimensional vortex rings. More complex structures of vortex clusters, such as vortex flake structures, and standing wave motions, also emerge under specific quantum numbers. These results demonstrate the ability to control SC vortex motion and phase structures through structured light, offering potential applications in quantum fluids and optical control of superconducting states. Our findings present a diagram that links light’s quantum numbers to the resulting SC vortex dynamics, highlighting the capacity of light to transfer its symmetry onto superconducting condensates. We point out that this approach represents the extension of printing to quantum printing by light in a coherent state of electrons.

Citation: Tien-Tien Yeh, Hennadii Yerzhakov, Logan Bishop-Van Horn, Srinivas Raghu, Alexander Balatsky, "Quantum printing and induced vorticity in superconductors II: Laguerre-Gaussian beam", Physical Review Research 7, 043112 (2025). https://doi.org/10.1103/dqv7-w2w4

Quantum printing and induced vorticity in superconductors I: Linearly polarized light

Published in Physical Review Research, 2025

We propose an approach to use linearly polarized light to imprint superconducting (SC) vortices. Within the framework of the generalized time-dependent Ginzburg-Landau equations, we demonstrate the induction of the coherent vortex pairs that move in phase with electromagnetic wave oscillations. The overall vorticity of the superconductor remains zero throughout the cycle. Our results uncover rich multiscale dynamics of SC vorticity and suggest optical applications for various types of structured light. In a departure from classical laser printing, the laser printing proposed here can be viewed as quantum printing where we induce quantum excitations in the SC liquid.

Citation: Tien-Tien Yeh, Hennadii Yerzhakov, Logan Bishop-Van Horn, Srinivas Raghu, Alexander Balatsky, "Quantum printing and induced vorticity in superconductors I: Linearly polarized light", Physical Review Research 7, 043111 (2025). https://doi.org/10.1103/k9m4-h474

Characterization of Two Fast-Turnaround Dry Dilution Refrigerators for Scanning Probe Microscopy

Published in Journal of Low Temperature Physics, 2024

Low-temperature scanning probe microscopes (SPMs) are critical for the study of quantum materials and quantum information science. Due to the rising costs of helium, cryogen-free cryostats have become increasingly desirable. However, they typically suffer from comparatively worse vibrations than cryogen-based systems, necessitating the understanding and mitigation of vibrations for SPM applications. Here we demonstrate the construction of two cryogen-free dilution refrigerator SPMs with minimal modifications to the factory default and we systematically characterize their vibrational performance. We measure the absolute vibrations at the microscope stage with geophones and use both microwave impedance microscopy and a scanning single-electron transistor to independently measure tip-sample vibrations. Additionally, we implement customized filtering and thermal anchoring schemes and characterize the cooling power at the scanning stage and the tip electron temperature. This work serves as a reference to researchers interested in cryogen-free SPMs, as such characterization is not standardized in the literature or available from manufacturers.

Citation: Mark E. Barber, Yifan Li, Jared Gibson, Jiachen Yu, Zhanzhi Jiang, Yuwen Hu, Zhurun Ji, Nabhanila Nandi, Jesse C. Hoke, Logan Bishop-Van Horn, Gilbert R. Arias, Dale J. Van Harlingen, Kathryn A. Moler, Zhi-Xun Shen, Angela Kou, and Benjamin E. Feldman "Characterization of Two Fast-Turnaround Dry Dilution Refrigerators for Scanning Probe Microscopy", Journal of Low Temperature Physics 215, 1-23 (2024). http://dx.doi.org/10.1007/s10909-023-03035-4

Vortex dynamics induced by scanning SQUID susceptometry

Published in Physical Review B, 2023

In this paper, we used both SuperScreen (a 2D London-Maxwell solver) and pyTDGL (a 2D time-dependent Ginzburg-Landau solver) to simulate the dynamics of quantum vortices generated in a superconducting thin film by a local magnetic field source. Our modeling allowed us to identify distinct “fingerprints” of the dynamics of a small number of vortex-antivortex pairs generated during measurements of the local magnetic response of a superconducting thin film close to its critical temperature.

Citation: Logan Bishop-Van Horn*, Eli Mueller*, and Kathryn A. Moler, "Vortex dynamics induced by scanning SQUID susceptometry ", Phys. Rev. B 107, 224509 (2023). https://doi.org/10.1103/PhysRevB.107.224509

Local imaging of diamagnetism in proximity-coupled niobium nanoisland arrays on gold thin films

Published in Physical Review B, 2022

This paper describes measurements and modeling of the local magnetic response of disordered arrays of proximity-coupled superconducting nano-islands.

Citation: Logan Bishop-Van Horn*, Irene P. Zhang*, Emily N. Waite, Ian Mondragon-Shem, Scott Jensen, Junseok Oh, Tom Lippman, Malcolm Durkin, Taylor L. Hughes, Nadya Mason, Kathryn A. Moler, and Ilya Sochnikov, "Local imaging of diamagnetism in proximity-coupled niobium nanoisland arrays on gold thin films", Phys. Rev. B 106, 054521 (2022) (Editors' Suggestion). https://doi.org/10.1103/PhysRevB.106.054521

SuperScreen: An open-source package for simulating the magnetic response of two-dimensional superconducting devices

Published in Computer Physics Communications, 2022

This paper introduces SuperScreen, an open-source Python package for simulating the response of 2D superconductors to trapped flux and applied time-independent or quasi-DC magnetic fields for any value of the effective magnetic penetration depth, Λ.

Citation: Logan Bishop-Van Horn and Kathryn A. Moler , "SuperScreen: An open-source package for simulating the magnetic response of two-dimensional superconducting devices", Computer Physics Communications Volume 280, November 2022, 108464. https://doi.org/10.1016/j.cpc.2022.108464

Imaging anisotropic vortex dynamics in FeSe

Published in Physical Review B, 2019

This paper describes measurements and modeling of anisotropic vortex pinning in the iron-based superconductor FeSe.

Citation: Irene P. Zhang, Johanna C. Palmstrom, Hilary Noad, Logan Bishop-Van Horn, Yusuke Iguchi, Zheng Cui, Eli Mueller, John R. Kirtley, Ian R. Fisher, and Kathryn A. Moler, "Imaging anisotropic vortex dynamics in FeSe", Phys. Rev. B 100, 024514 (2019). https://doi.org/10.1103/PhysRevB.100.024514

Cryogen-free variable temperature scanning SQUID microscope

Published in Review of Scientific Instruments, 2019

This paper describes the construction of a variable temperature scanning SQUID microscope in a dry cryostat, enabling precision magnetometry and susceptometry at sample temperatures from 2.8 K to over 100 K.

Citation: Logan Bishop-Van Horn, Zheng Cui, John R. Kirtley, and Kathryn A. Moler , "Cryogen-free variable temperature scanning SQUID microscope", Review of Scientific Instruments 90, 063705 (2019). https://doi.org/10.1063/1.5085008

The signature of inhomogeneous superconductivity

Published in Journal of Low Temperature Physics, 2016

This work describes the RF magnetic response of organic superconductors at low temperature and high magnetic field, where the field is applied parallel to the quasi-2D superconducting layers of the organic crystal. Under certain conditions, these materials are thought to host an unconventional phase known as the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase, in which Cooper pairs acquire a finite center of mass momentum leading to a spatially modulated superconducting order parameter.

Citation: Charles C. Agosta, Logan Bishop-Van Horn, Max Newman, "The Signature of Inhomogeneous Superconductivity", Journal of Low Temperature Physics 185, 220–229 (2016). https://doi.org/10.1007/s10909-016-1657-y