@article{21340, abstract = {Equilibrium quantum systems are often described by a gas of weakly interacting normal modes. Bringing such systems far from equilibrium, however, can drastically enhance mode-to-mode interactions. Understanding the resulting liquid is a fundamental question for quantum statistical mechanics and a practical question for engineering driven quantum devices. To tackle this question, we probe the non-equilibrium kinetics of one-dimensional plasmons in a long chain of Josephson junctions. We introduce multimode spectroscopy to controllably study the departure from equilibrium, witnessing the evolution from pairwise coupling between plasma modes at weak driving to dramatic, high-order, cascaded couplings at strong driving. Scaling to many-mode drives, we stimulate interactions between hundreds of modes, resulting in near-continuum internal dynamics. Imaging the resulting non-equilibrium plasmon populations, we then resolve the nonlocal redistribution of energy in the response to a weak perturbation—an explicit verification of the emergence of a strongly interacting, non-equilibrium liquid of plasmons.}, author = {Bubis, Anton and Vigliotti, Lucia and Serbyn, Maksym and Higginbotham, Andrew P}, issn = {2375-2548}, journal = {Science Advances}, number = {7}, publisher = {American Association for the Advancement of Science}, title = {{Non-equilibrium plasmon liquid in a Josephson junction chain}}, doi = {10.1126/sciadv.ady7222}, volume = {12}, year = {2026}, } @article{22323, abstract = {Arrays of Josephson junctions can be tuned through anomalous metallic, quantum-critical, and insulating regimes. We introduce an alternative experimental probe, capturing microwave radiation across all three regimes, using a two-dimensional array of superconductor-semiconductor hybrid Josephson junctions as a model system. Our approach allows calibration of the sample’s circuit parameters and provides isolation from measurement back-action effects. We measure the radiation temperature of the anomalous metal and find that it is hotter than both the quantum-critical and insulating regimes. We further show that the anomalous metallic regime is more susceptible to additional heating than other regimes, explaining its emergence in otherwise thermalized systems. Turning to the quantum-critical regime, we discover nonlinear scaling of radiative noise with applied bias, consistent with theoretical predictions of universal nonequilibrium behavior at quantum-critical points.}, author = {Galvin, Kristen W and Bubis, Anton and Mikalsen, Melissa and Schiela, William F. and Elfeky, Bassel H. and Strickland, William M. and Phan, Duc T and Shabani, Javad and Higginbotham, Andrew P}, issn = {2331-7019}, journal = {Physical Review Applied}, publisher = {American Physical Society}, title = {{Microwave radiometry of a quantum-critical hybrid Josephson array}}, doi = {10.1103/75bl-mm3b}, volume = {26}, year = {2026}, } @article{19026, abstract = {The back-action damping of mechanical motion by electromagnetic radiation is typically overwhelmed by internal loss channels unless demanding experimental ingredients such as superconducting resonators, high-quality optical cavities, or large magnetic fields are employed. Here we demonstrate the first room temperature, cavity-free, all-electric device where back-action damping exceeds internal loss, enabled by a mechanically compliant parallel-plate capacitor with a nanoscale plate separation and an aspect ratio exceeding 1,000. The device has 4 orders of magnitude lower insertion loss than a comparable commercial quartz crystal and achieves a position imprecision rivaling optical interferometers. With the help of a back-action isolation scheme, we observe radiative cooling of mechanical motion by a remote cryogenic load. This work provides a technologically accessible route to high-precision sensing, transduction, and signal processing.}, author = {Puglia, Denise and Odessey, Rachel H and Burns, Peter and Luhmann, Niklas and Schmid, Silvan and Higginbotham, Andrew P}, issn = {1530-6992}, journal = {Nano Letters}, number = {7}, pages = {2749--2755}, publisher = {American Chemical Society}, title = {{Room temperature, cavity-free capacitive strong coupling to mechanical motion}}, doi = {10.1021/acs.nanolett.4c05796}, volume = {25}, year = {2025}, } @article{20324, abstract = {We report relaxation oscillations in a one-dimensional array of Josephson junctions, wherein the array dynamically switches between low-current and high-current states. The oscillations are current-voltage dual to those ordinarily observed in single junctions. The current-voltage dual circuit quantitatively accounts for temporal dynamics of the array, including the dependence on biasing conditions. Injection locking of the oscillations results in well-developed current plateaux. A thermal model explains the self-consistent reduction of the superconducting gap due to overheating of the array in the high-current state. Our work suggests that overheating determines the switching from the high-current state to the low-current state.}, author = {Mukhopadhyay, Soham and Lancheros Naranjo, Diego A and Senior, Jorden L and Higginbotham, Andrew P}, issn = {2331-7019}, journal = {Physical Review Applied}, publisher = {American Physical Society}, title = {{Dual relaxation oscillations in a Josephson-junction array}}, doi = {10.1103/qvls-7s3q}, volume = {24}, year = {2025}, } @article{15367, abstract = {Two-dimensional semiconductor-superconductor heterostructures form the foundation of numerous nanoscale physical systems. However, measuring the properties of such heterostructures, and characterizing the semiconductor in-situ is challenging. A recent experimental study by [Phys. Rev. Lett. 128, 107701 (2022)] was able to probe the semiconductor within the heterostructure using microwave measurements of the superfluid density. This work revealed a rapid depletion of superfluid density in semiconductor, caused by the in-plane magnetic field which in presence of spin-orbit coupling creates so-called Bogoliubov Fermi surfaces. The experimental work used a simplified theoretical model that neglected the presence of non-magnetic disorder in the semiconductor, hence describing the data only qualitatively. Motivated by experiments, we introduce a theoretical model describing a disordered semiconductor with strong spin-orbit coupling that is proximitized by a superconductor. Our model provides specific predictions for the density of states and superfluid density. Presence of disorder leads to the emergence of a gapless superconducting phase, that may be viewed as a manifestation of Bogoliubov Fermi surface. When applied to real experimental data, our model showcases excellent quantitative agreement, enabling the extraction of material parameters such as mean free path and mobility, and estimating g-tensor after taking into account the orbital contribution of magnetic field. Our model can be used to probe in-situ parameters of other superconductor-semiconductor heterostructures and can be further extended to give access to transport properties.}, author = {Babkin, Serafim and Higginbotham, Andrew P and Serbyn, Maksym}, issn = {2542-4653}, journal = {SciPost Physics}, number = {5}, publisher = {SciPost Foundation}, title = {{Proximity-induced gapless superconductivity in two-dimensional Rashba semiconductor in magnetic field}}, doi = {10.21468/scipostphys.16.5.115}, volume = {16}, year = {2024}, } @article{17235, abstract = {We demonstrate ion irradiation by argon or gallium as a wafer-scale post-processing method to increase disorder in superconducting thin films. We study several widely used superconductors, both single-elements and compounds. We show that ion irradiation increases normal-state resistivity in all our films, which is expected to enable tuning their superconducting properties, for example, toward a higher kinetic inductance. We observe an increase in superconducting transition temperature for Al and MoSi and a decrease for Nb, NbN, and TiN. In MoSi, ion irradiation also improves the mixing of the two materials. We demonstrate the fabrication of an amorphous and homogeneous film of MoSi with uniform thickness, which is promising, for example, for superconducting nanowire single-photon detectors.}, author = {Kohopää, Katja and Ronzani, Alberto and Jabdaraghi, Robab Najafi and Bera, Arijit and Ribeiro, Mário and Hazra, Dibyendu and Senior, Jorden L and Prunnila, Mika and Govenius, Joonas and Lehtinen, Janne S. and Kemppinen, Antti}, issn = {2166-532X}, journal = {APL Materials}, number = {7}, publisher = {AIP Publishing}, title = {{Effect of ion irradiation on superconducting thin films}}, doi = {10.1063/5.0202851}, volume = {12}, year = {2024}, } @article{17480, abstract = {One of the most promising approaches towards large-scale quantum computation uses devices based on many Josephson junctions. Yet, even today, open questions regarding the single junction remain unsolved, such as the detailed understanding of the quantum phase transitions, the coupling of the Josephson junction to the environment or how to improve the coherence of a superconducting qubit. Here we design and build an engineered on-chip reservoir connected to a Josephson junction that acts as an efficient bolometer for detecting the Josephson radiation under non-equilibrium, that is, biased conditions. The bolometer converts the a.c. Josephson current at microwave frequencies up to about 100 GHz into a temperature rise measured by d.c. thermometry. A circuit model based on realistic parameter values captures both the current–voltage characteristics and the measured power quantitatively. The present experiment demonstrates an efficient, wide-band, thermal detection scheme of microwave photons and provides a sensitive detector of Josephson dynamics beyond the standard conductance measurements.}, author = {Karimi, Bayan and Steffensen, Gorm Ole and Higginbotham, Andrew P and Marcus, Charles M. and Levy Yeyati, Alfredo and Pekola, Jukka P.}, issn = {1748-3395}, journal = {Nature Nanotechnology}, pages = {1613--1618}, publisher = {Springer Nature}, title = {{Bolometric detection of Josephson radiation}}, doi = {10.1038/s41565-024-01770-7}, volume = {19}, year = {2024}, } @phdthesis{17881, abstract = {This work can be broadly classified into the study of critical phenomena in a one dimensional array of Josephson junctions. While we study quantum criticality when the array is in thermal equilibrium at zero bias, the non-equilibrium study involves understanding the bistability of the array at a critical non-zero bias. This work furthers our knowledge in understanding quantum critical behaviour at finite temperatures in a one dimensional Josephson array, while also establishing relaxation behaviour dual to that observed in a single Josephson junction. Chapter 1 briefly introduces the model to understand superconductor-insulator phase transition in a one dimensional Josephson array and points out the state of the field from where we started our zero-bias experiments. In this context it discusses the phase-charge duality observed in a Josephson array and its dual hysteretic behaviour to that of a single junction, setting the ground for our non-equilibrium study of the array. Chapter 2 shows the experimental setup and the chip layout of the device we measured. In chapter 3 we show that, unlike the typical quantum-critical broadening scenario, in one dimensional Josephson arrays temperature dramatically shifts the critical region. This shift leads to a regime of superconductivity at high temperature, arising from the melted zero-temperature insulator. Our results quantitatively explain the low-temperature onset of superconductivity in nominally insulating regimes, and the transition to the strongly insulating phase. We further present, to our knowledge, the first understanding of the onset of anomalous-metallic resistance saturation [30]. This work demonstrates a non-trivial interplay between thermal effects and quantum criticality. A practical consequence is that, counterintuitively, the coherence of high-impedance quantum circuits is expected to be stabilized by thermal fluctuations. In chapter 4, we show relaxation oscillations in a current-biased one dimensional array of Josephson junctions. These oscillations are well described by a circuit model, dual to the ordinary Josephson relaxation oscillations [72]. Injection locking these oscillations results in current plateaux. The relaxation step is found to obey a characteristic self-consistent relation, suggesting that it is governed by overheating effects. Chapter 5 describes the various checks and analysis we performed to support our conclusions made in chapters 3 and 4. Finally, chapter 6 describes the nanofabrication steps and the finite element electromagnetic simulations we performed to fabricate our devices.}, author = {Mukhopadhyay, Soham}, isbn = {978-3-99078-043-5}, issn = {2663-337X}, pages = {82}, publisher = {Institute of Science and Technology Austria}, title = {{Thermal effects in one dimensional Josephson chains}}, doi = {10.15479/at:ista:17881}, year = {2024}, } @unpublished{18057, abstract = {We report relaxation oscillations in a one-dimensional array of Josephson junctions. The oscillations are circuit-dual to those ordinarily observed in single junctions. The dual circuit quantitatively accounts for temporal dynamics of the array, including the dependence on biasing conditions. Injection locking the oscillations results in well-developed current plateaux. A thermal model explains the relaxation step of the oscillations.}, author = {Mukhopadhyay, Soham and Lancheros Naranjo, Diego A and Senior, Jorden L and Higginbotham, Andrew P}, booktitle = {arXiv}, title = {{Dual relaxation oscillations in a Josephson junction array}}, doi = {10.48550/arXiv.2408.07829}, year = {2024}, } @phdthesis{18104, abstract = {We introduce a new all-electric platform, that strong couples light to mechanical motion by ensuring that the external environmental coupling dominates over internal mechanical dissipation. The system only has three everyday components: AC, DC, and a fip-chip, in which a metallized silicon nitride membrane is fipped on top of the device under test. This everyday electromechanical device can be operated at low or room temperature and has 10000× lower insertion loss than a comparable commercial quartz crystal, achieves a position imprecision matching state-of-the-art optical interferometer, and enables remote cooling of mechanical motion. The spatial properties of higher order mechanical modes are a promising feature for reconstructing unknown charge distributions. }, author = {Puglia, Denise}, issn = {2663-337X}, pages = {63}, publisher = {Institute of Science and Technology Austria}, title = {{Everyday electromechanics: Capacitive strong coupling to mechanical motion}}, doi = {10.15479/at:ista:18104}, year = {2024}, } @unpublished{18143, abstract = {Strong optomechanical coupling -- a regime where mechanical motion is damped by environmental radiation -- has traditionally required demanding experimental ingredients such as superconducting resonators, high-quality optical cavities, or large magnetic fields. Here we demonstrate a room temperature, cavity-free, all-electric device reaching this regime at radio frequencies, enabled by a mechanically compliant parallel-plate capacitor with a nanoscale plate separation and an aspect ratio exceeding 1,000. The device has four orders of magnitude lower insertion loss than a comparable commercial quartz crystal, and achieves a position imprecision rivaling an optical interferometer. With the help of a back-action isolation scheme, we observe radiative cooling of mechanical motion by a remote cryogenic load. This work provides a technologically accessible route to high-precision sensing, transduction, and signal processing.}, author = {Puglia, Denise and Odessey, Rachel H and Burns, Peter S. and Luhmann, Niklas and Schmid, Silvan and Higginbotham, Andrew P}, booktitle = {arXiv}, title = {{Room temperature, cavity-free capacitive strong coupling to mechanical motion}}, doi = {10.48550/arXiv.2407.15314}, year = {2024}, } @article{17183, abstract = {The photon blockade breakdown in a continuously driven cavity QED system has been proposed as a prime example for a first-order driven-dissipative quantum phase transition. However, the predicted scaling from a microscopic behavior—dominated by quantum fluctuations—to a macroscopic one—characterized by stable phases—and the associated exponents and phase diagram have not been observed so far. In this work we couple a single transmon qubit with a fixed coupling strength 𝑔 to a superconducting cavity that is in situ bandwidth 𝜅 tunable to controllably approach this thermodynamic limit. Even though the system remains microscopic, we observe its behavior becoming increasingly macroscopic as a function of 𝑔/𝜅. For the highest realized 𝑔/𝜅 of approximately 287, the system switches with a characteristic timescale as long as 6 s between a bright coherent state with approximately 8×103 intracavity photons and the vacuum state. This exceeds the microscopic timescales by 6 orders of magnitude and approaches the perfect hysteresis expected between two macroscopic attractors in the thermodynamic limit. These findings and interpretation are qualitatively supported by neoclassical theory and large-scale quantum-jump Monte Carlo simulations. Besides shedding more light on driven-dissipative physics in the limit of strong light-matter coupling, this system might also find applications in quantum sensing and metrology.}, author = {Sett, Riya and Hassani, Farid and Phan, Duc T and Barzanjeh, Shabir and Vukics, Andras and Fink, Johannes M}, issn = {2691-3399}, journal = {PRX Quantum}, number = {1}, publisher = {American Physical Society}, title = {{Emergent macroscopic bistability induced by a single superconducting qubit}}, doi = {10.1103/prxquantum.5.010327}, volume = {5}, year = {2024}, } @misc{18978, abstract = {Data analysis files for the manuscript "Emergent Macroscopic Bistability Induced by a Single Superconducting Qubit". This contains the raw data and the data analysis files for generating the figures in the manuscript. Figure1 file - The raw data of cavity transmission spectra for 6 different kappas are there. They are fitted with input-output theory in the python file. Figure2 file - The raw data at 8 MHz kappa are included. all hte figures in figure 2 are generated in the python file Figure3 file - The raw data of PBB single shot measurements at all kappas are included. The detailed analysis and the Figure3 generated for the paper are all in the python analysis file. Also, thefiles containing the time-evolution of the intensity from Master Equation solution are included. Figure4 file - The raw data at 2.6 MHz for different drive detunings and the corresponding analyses are included. And the python file includes the analysis of the experimental data as well as approximate neoclassical equations solutions for 2-level and 3-level transmons are included. }, author = {Sett, Riya and Hassani, Farid and Phan, Duc T and Barzanjeh, Shabir and Vukics, Andras and Fink, Johannes M}, publisher = {Zenodo}, title = {{Data Analysis files for "Emergent Macroscopic Bistability Induced by a Single Superconducting Qubit"}}, doi = {10.5281/ZENODO.10518320}, year = {2024}, } @article{12913, abstract = {The coexistence of gate-tunable superconducting, magnetic and topological orders in magic-angle twisted bilayer graphene provides opportunities for the creation of hybrid Josephson junctions. Here we report the fabrication of gate-defined symmetry-broken Josephson junctions in magic-angle twisted bilayer graphene, where the weak link is gate-tuned close to the correlated insulator state with a moiré filling factor of υ = −2. We observe a phase-shifted and asymmetric Fraunhofer pattern with a pronounced magnetic hysteresis. Our theoretical calculations of the junction weak link—with valley polarization and orbital magnetization—explain most of these unconventional features. The effects persist up to the critical temperature of 3.5 K, with magnetic hysteresis observed below 800 mK. We show how the combination of magnetization and its current-induced magnetization switching allows us to realise a programmable zero-field superconducting diode. Our results represent a major advance towards the creation of future superconducting quantum electronic devices.}, author = {Díez-Mérida, J. and Díez-Carlón, A. and Yang, S. Y. and Xie, Y. M. and Gao, X. J. and Senior, Jorden L and Watanabe, K. and Taniguchi, T. and Lu, X. and Higginbotham, Andrew P and Law, K. T. and Efetov, Dmitri K.}, issn = {2041-1723}, journal = {Nature Communications}, publisher = {Springer Nature}, title = {{Symmetry-broken Josephson junctions and superconducting diodes in magic-angle twisted bilayer graphene}}, doi = {10.1038/s41467-023-38005-7}, volume = {14}, year = {2023}, } @phdthesis{14547, abstract = {Superconductor-semiconductor heterostructures currently capture a significant amount of research interest and they serve as the physical platform in many proposals towards topological quantum computation. Despite being under extensive investigations, historically using transport techniques, the basic properties of the interface between the superconductor and the semiconductor remain to be understood. In this thesis, two separate studies on the Al-InAs heterostructures are reported with the first focusing on the physics of the material motivated by the emergence of a new phase, the Bogoliubov-Fermi surface. The second focuses on a technological application, a gate-tunable Josephson parametric amplifier. In the first study, we investigate the hypothesized unconventional nature of the induced superconductivity at the interface between the Al thin film and the InAs quantum well. We embed a two-dimensional Al-InAs hybrid system in a resonant microwave circuit allowing measurements of change in inductance. The behaviour of the resonance in a range of temperature and in-plane magnetic field has been studied and compared with the theory of conventional s-wave superconductor and a two-component theory that includes both contribution of the $s$-wave pairing in Al and the intraband $p \pm ip$ pairing in InAs. Measuring the temperature dependence of resonant frequency, no discrepancy is found between data and the conventional theory. We observe the breakdown of superconductivity due to an applied magnetic field which contradicts the conventional theory. In contrast, the data can be captured quantitatively by fitting to a two-component model. We find the evidence of the intraband $p \pm ip$ pairing in the InAs and the emergence of the Bogoliubov-Fermi surfaces due to magnetic field with the characteristic value $B^* = 0.33~\mathrm{T}$. From the fits, the sheet resistance of Al, the carrier density and mobility in InAs are determined. By systematically studying the anisotropy of the circuit response, we find weak anisotropy for $B < B^*$ and increasingly strong anisotropy for $B > B^*$ resulting in a pronounced two-lobe structure in polar plot of frequency versus field angle. Strong resemblance between the field dependence of dissipation and superfluid density hints at a hidden signature of the Bogoliubov-Fermi surface that is burried in the dissipation data. In the second study, we realize a parametric amplifier with a Josephson field effect transistor as the active element. The device's modest construction consists of a gated SNS weak link embedded at the center of a coplanar waveguide resonator. By applying a gate voltage, the resonant frequency is field-effect tunable over a range of 2 GHz. Modelling the JoFET minimally as a parallel RL circuit, the dissipation introduced by the JoFET can be quantitatively related to the gate voltage. We observed gate-tunable Kerr nonlinearity qualitatively in line with expectation. The JoFET amplifier has 20 dB of gain, 4 MHz of instantaneous bandwidth, and a 1dB compression point of -125.5 dBm when operated at a fixed resonant frequency. In general, the signal-to-noise ratio is improved by 5-7 dB when the JoFET amplifier is activated compared. The noise of the measurement chain and insertion loss of relevant circuit elements are calibrated to determine the expected and the real noise performance of the JoFET amplifier. As a quantification of the noise performance, the measured total input-referred noise of the JoFET amplifier is in good agreement with the estimated expectation which takes device loss into account. We found that the noise performance of the device reported in this document approaches one photon of total input-referred added noise which is the quantum limit imposed in nondegenerate parametric amplifier.}, author = {Phan, Duc T}, issn = {2663-337X}, keywords = {superconductor-semiconductor, superconductivity, Al, InAs, p-wave, superconductivity, JPA, microwave}, pages = {80}, publisher = {Institute of Science and Technology Austria}, title = {{Resonant microwave spectroscopy of Al-InAs}}, doi = {10.15479/14547}, year = {2023}, } @article{13264, abstract = {We build a parametric amplifier with a Josephson field-effect transistor (JoFET) as the active element. The resonant frequency of the device is field-effect tunable over a range of 2 GHz. The JoFET amplifier has 20 dB of gain, 4 MHz of instantaneous bandwidth, and a 1-dB compression point of -125.5 dBm when operated at a fixed resonance frequency. }, author = {Phan, Duc T and Falthansl-Scheinecker, Paul and Mishra, Umang and Strickland, W. M. and Langone, D. and Shabani, J. and Higginbotham, Andrew P}, issn = {2331-7019}, journal = {Physical Review Applied}, number = {6}, publisher = {American Physical Society}, title = {{Gate-tunable superconductor-semiconductor parametric amplifier}}, doi = {10.1103/PhysRevApplied.19.064032}, volume = {19}, year = {2023}, } @article{14032, abstract = {Arrays of Josephson junctions are governed by a competition between superconductivity and repulsive Coulomb interactions, and are expected to exhibit diverging low-temperature resistance when interactions exceed a critical level. Here we report a study of the transport and microwave response of Josephson arrays with interactions exceeding this level. Contrary to expectations, we observe that the array resistance drops dramatically as the temperature is decreased—reminiscent of superconducting behaviour—and then saturates at low temperature. Applying a magnetic field, we eventually observe a transition to a highly resistive regime. These observations can be understood within a theoretical picture that accounts for the effect of thermal fluctuations on the insulating phase. On the basis of the agreement between experiment and theory, we suggest that apparent superconductivity in our Josephson arrays arises from melting the zero-temperature insulator.}, author = {Mukhopadhyay, Soham and Senior, Jorden L and Saez Mollejo, Jaime and Puglia, Denise and Zemlicka, Martin and Fink, Johannes M and Higginbotham, Andrew P}, issn = {1745-2481}, journal = {Nature Physics}, keywords = {General Physics and Astronomy}, pages = {1630--1635}, publisher = {Springer Nature}, title = {{Superconductivity from a melted insulator in Josephson junction arrays}}, doi = {10.1038/s41567-023-02161-w}, volume = {19}, year = {2023}, } @article{10851, abstract = {Superconductor-semiconductor hybrid devices are at the heart of several proposed approaches to quantum information processing, but their basic properties remain to be understood. We embed a twodimensional Al-InAs hybrid system in a resonant microwave circuit, probing the breakdown of superconductivity due to an applied magnetic field. We find a fingerprint from the two-component nature of the hybrid system, and quantitatively compare with a theory that includes the contribution of intraband p±ip pairing in the InAs, as well as the emergence of Bogoliubov-Fermi surfaces due to magnetic field. Separately resolving the Al and InAs contributions allows us to determine the carrier density and mobility in the InAs.}, author = {Phan, Duc T and Senior, Jorden L and Ghazaryan, Areg and Hatefipour, M. and Strickland, W. M. and Shabani, J. and Serbyn, Maksym and Higginbotham, Andrew P}, issn = {1079-7114}, journal = {Physical Review Letters}, keywords = {General Physics and Astronomy}, number = {10}, publisher = {American Physical Society}, title = {{Detecting induced p±ip pairing at the Al-InAs interface with a quantum microwave circuit}}, doi = {10.1103/physrevlett.128.107701}, volume = {128}, year = {2022}, } @article{10589, abstract = {Superconducting devices ubiquitously have an excess of broken Cooper pairs, which can hamper their performance. It is widely believed that external radiation is responsible but a study now suggests there must be an additional, unknown source.}, author = {Higginbotham, Andrew P}, issn = {1745-2481}, journal = {Nature Physics}, keywords = {superconducting devices, superconducting properties and materials}, pages = {126}, publisher = {Springer Nature}, title = {{A secret source}}, doi = {10.1038/s41567-021-01459-x}, volume = {18}, year = {2022}, } @misc{13080, abstract = {Data for the manuscript 'Closing of the Induced Gap in a Hybrid Superconductor-Semiconductor Nanowire' ([2006.01275] Closing of the Induced Gap in a Hybrid Superconductor-Semiconductor Nanowire (arxiv.org)) We upload a pdf with extended data sets, and the raw data for these extended datasets as well.}, author = {Puglia, Denise and Martinez, Esteban and Menard, Gerbold and Pöschl, Andreas and Gronin, Sergei and Gardner, Geoffrey and Kallaher, Ray and Manfra, Michael and Marcus, Charles and Higginbotham, Andrew P and Casparis, Lucas}, publisher = {Zenodo}, title = {{Data for 'Closing of the Induced Gap in a Hybrid Superconductor-Semiconductor Nanowire}}, doi = {10.5281/ZENODO.4592435}, year = {2021}, }