Owen Medeiros

Research

Research and publications on superconducting detectors and electronics, produced while working in the Quantum Nanostructures and Nanofabrication Group at MIT.

Theses

Doctoral thesis

Superconducting Nanowire Integrated Circuits for Scalable Cryogenic Memory PhD, Electrical Engineering and Computer Science — MIT (2025). Advisor: Professor Karl Berggren.

Superconducting nanowire integrated circuits (SNICs) are a promising class of cryogenic electronics that harness the zero resistance, high kinetic inductance, and nanoscale geometry of ultrathin superconducting wires to implement logic, memory, amplification, and sensing with minimal energy dissipation. Unlike Josephson-junction-based circuits, SNICs support compact, planar layouts compatible with single-layer fabrication and operation in unshielded cryogenic environments.

This thesis develops superconducting nanowire memory (SNM) as a scalable implementation of SNICs. A modular cell architecture is introduced, exploiting hysteretic switching and inductive asymmetry to enable nonvolatile digital state storage with zero static power consumption. A hierarchical design framework is established, combining automated layout generation, electrothermal simulation in LTspice, and microscopic modeling using the time-dependent Ginzburg–Landau (TDGL) formalism.

To enable scalable integration, this work implements a row–column SNM array layout and demonstrates fabrication across full 4-inch wafers using a planar, single-layer process. Cryogenic measurements validate reliable operation in both single cells and multi-cell arrays, confirming the predictive accuracy of the design and modeling framework. Tradeoffs in bias current levels, pulse timing, and read/write conditions are systematically evaluated through cryogenic measurements, revealing their impact on bit error rate, operational margins, and energy efficiency across single cells and arrays.

Together, these contributions establish SNICs as a viable and extensible platform for cryogenic memory, providing the tools, models, and infrastructure needed to enable broader adoption in quantum computing, neuromorphic systems, and other energy-constrained cryogenic applications.

Master’s thesis

Investigation of Thin Film Supercurrent and Photodetection in Wide Niobium Nitride Wires MS, Electrical Engineering and Computer Science — MIT (2022). Advisor: Professor Karl Berggren.

Over the past two decades, superconducting nanowire single photon detectors have become the dominant platform for detection at telecommunication wavelengths. Despite their practical success, the theoretical framework that describes the detection mechanism within the nanowire is continually evolving. Early phenomenological models suggested that a hot region forms across the superconducting strip after the arrival of a photon, producing a measurable voltage only if the diameter of the hot region extends across the width of the strip. However, predictions based on the kinetic-equation approach showed that within a certain operating regime detection no longer depends on the strip’s width. This prediction was later supported by the experimental demonstration of single photon detection in strips 1–3 μm wide. The ability to fabricate detectors with larger widths would allow for higher signal to noise ratios as well as higher fabrication yield compared to narrow wires. These advantages could potentially unlock some long sought after applications of single photon detectors such as large area detectors or >kilopixel arrays of detectors. In order to produce wide wire detectors the design and material properties must be well optimized. This thesis covers the development of wide single photon detectors using nitrogen-rich niobium nitride.

Publications

2026

  1. A scalable superconducting nanowire memory array with row–column addressing Nature Electronics, 1–9 (2026)
  2. Reconfigurable Superconducting Logic for On-Chip Photon Coincidence Detection arXiv preprint arXiv:2604.22101 (2026)

2025

  1. A superconducting full-wave bridge rectifier Nature Electronics, 8(5), 417–425 (2025)
  2. Time-tagging data acquisition system for testing superconducting electronics based on an RFSoC and custom analog frontend Journal of Instrumentation, 20(09), P09018 (2025)
  3. High-Fidelity Control of a Strongly Coupled Electro-Nuclear Spin-Photon Interface arXiv preprint arXiv:2505.09267 (2025)
  4. Superconducting Nanowire Integrated Circuits for Scalable Cryogenic Memory PhD Thesis, Massachusetts Institute of Technology (2025)
  5. Parameter extraction for a SPICE model of an hTron superconducting thermal switch Physical Review Applied, 24(2), 024020 (2025)
  6. Ab initio modeling of nonequilibrium dynamics in superconducting detectors and qubits Physical Review B, 112(17), 174512 (2025)
  7. Single-photon detectors on arbitrary photonic substrates ACS Photonics, 12(5), 2325–2330 (2025)
  8. Building blocks for quantum information processing with color centers in silicon CLEO: Science and Innovations, SS193_1 (2025)

2024

  1. Nanocryotron ripple counter integrated with a superconducting nanowire single-photon detector for megapixel arrays Physical Review Applied, 22(2), 024020 (2024)
  2. Molybdenum Silicide Superconducting Nanowire Single-Photon Detectors on Lithium Niobate Waveguides ACS Photonics, 11(2), 356–361 (2024)
  3. Technology development for a low-mass solar system and interstellar communications system Free-Space Laser Communications XXXVI, 12877, 526–544 (2024)
  4. Characterizing and modeling the influence of geometry on the performance of superconducting nanowire cryotrons IEEE Transactions on Applied Superconductivity, 35(5), 1–5 (2024)

2023

  1. Reduced ITO for transparent superconducting electronics Superconductor Science and Technology, 36(5), 055009 (2023)
  2. A nanocryotron memory and logic family Applied Physics Letters, 122(14) (2023)
  3. Single-photon detection using high-temperature superconductors Nature Nanotechnology, 18(4), 343–349 (2023)
  4. Integrated quantum memories at 1.3 K with tin-vacancy centers and photonic circuits CLEO: Science and Innovations, SM1K-6 (2023)
  5. A superconducting nanowire binary shift register Applied Physics Letters, 122(15) (2023)

2022

  1. Investigation of thin film supercurrent and photodetection in wide niobium nitride wires MS Thesis, Massachusetts Institute of Technology (2022)
  2. Reversible Tuning of Superconductivity in Ion-Gated NbN Ultrathin Films by Self-Encapsulation with a High-κ Dielectric Layer Physical Review Applied, 18(5), 054023 (2022)

2021

  1. A scalable superconducting nanowire memory cell and preliminary array test Superconductor Science and Technology, 34(3), 035003 (2021)
  2. NbN-gated GaN transistor technology for applications in quantum computing systems 2021 Symposium on VLSI Technology, 1–2 (2021)

2020

  1. Superconducting nanowire single-photon detector on thin-film lithium niobate photonic waveguide CLEO: Science and Innovations, SM4O-4 (2020)
  2. Control of bulk superconductivity via surface-bound electric fields in ion-gated niobium nitride thin films Proceedings of the 11th Conference “Solid State Surfaces and Interfaces”, 1, 67–69 (2020)

2019

  1. Measuring thickness in thin NbN films for superconducting devices Journal of Vacuum Science & Technology A, 37(4) (2019)

2016

  1. Affordable photolithography with biomedical applications 2016 IEEE MIT Undergraduate Research Technology Conference (URTC), 1–4 (2016)