Article
Optics
Alan Bregazzi, Paul Janin, Sean Dyer, James P. Mcgilligan, Oliver Burrow, Erling Riis, Deepak Uttamchandani, Ralf Bauer, Paul F. Griffin
Summary: We demonstrate the integration of MEMS scanning mirrors as active elements for local optical pumping of ultra-cold atoms in a magneto-optical trap. The MEMS mirrors steer a focused resonant beam through a cloud of trapped atoms, allowing for spatially selective fluorescence and two-dimensional control. This approach has potential applications in single atom selection, local optical pumping, and arbitrary cloud shaping, and is also promising for miniaturization and portable control systems in quantum optic experiments.
Article
Multidisciplinary Sciences
Lucas Schneider, Philip Beck, Levente Rozsa, Thore Posske, Jens Wiebe, Roland Wiesendanger
Summary: Spin chains proximitized by s-wave superconductors are predicted to enter a mini-gapped phase with topologically protected Majorana modes (MMs) localized at their ends. However, the presence of non-topological end states mimicking MM properties can hinder their unambiguous observation. Here, we report on a direct method to exclude the non-local nature of end states via scanning tunneling spectroscopy by introducing a locally perturbing defect on one of the chain's ends. We apply this method to particular end states observed in antiferromagnetic spin chains within a large minigap, thereby proving their topologically trivial character. A minimal model shows that, while wide trivial minigaps hosting end states are easily achieved in antiferromagnetic spin chains, unrealistically large spin-orbit coupling is required to drive the system into a topologically gapped phase with MMs. The methodology of perturbing candidate topological edge modes in future experiments is a powerful tool to probe their stability against local disorder. Spin chains on superconductors have been studied as a possible venue for zero-energy Majorana bound states at the ends of the chain. Here, the authors observe localized end states in antiferromagnetic chains, but rule out a Majorana origin of these states by perturbing them with local defects.
NATURE COMMUNICATIONS
(2023)
Article
Instruments & Instrumentation
Taemin Ahn, Sungmin Song, Ungdon Ham, Tae-Hwan Kim
Summary: Piezoelectric motors are commonly used in applications requiring precision positioning and miniaturization. Wear-induced cold welding is a common issue in long-term use, especially in vacuum environments. In this study, we investigated the practical reliability of various UHV-compatible lubricant coatings and found that polytetrafluoroethylene (PTFE) coating showed the most reliable long-term operation in vacuum, while other coatings eventually led to motor failure. Coating the slider surface with PTFE provides a simple and effective way to improve the long-term performance of UHV piezoelectric motors.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Materials Science, Multidisciplinary
Jonathan Op de Beeck, Jeroen E. Scheerder, Brian P. Geiser, Joseph H. Bunton, Robert M. Ulfig, David J. Larson, Paul van der Heide, Wilfried Vandervorst, Claudia Fleischmann
Summary: This study proposes three key steps to improve the spatial accuracy of reconstructed volume in heterogeneous systems. Firstly, scanning probe microscopy is used to determine the local curvature of heterogeneous emitters. Secondly, the cyclical relationship between scanning probe characterization and atom probe analysis is demonstrated. Lastly, advances in the development of an electrostatically driven reconstruction protocol are shown to enable reconstruction based on experimental tip shapes.
MICROSCOPY AND MICROANALYSIS
(2022)
Article
Construction & Building Technology
Yixing Ding, Yanmin Jia
Summary: This paper investigates the fracture behavior of ML15 cold heading steel based on the ductile fracture theory. Different types of specimens were designed and tested, and the micro fracture morphologies were examined using scanning electron microscopy. The Rice-Tracey model and Bai-Wierzbicki model were calibrated and used for finite element analysis, showing the feasibility of the calibrated fracture locus for metal failure analysis.
Article
Multidisciplinary Sciences
Pushpendra Singh, Pathik Sahoo, Komal Saxena, Jhimli Sarkar Manna, Kanad Ray, Subrata Ghosh, Anirban Bandyopadhyay
Summary: Hodgkin and Huxley demonstrated that a neuron's membrane alone can generate and transmit nerve spikes, with the time modulation mechanism still being a mystery. Filaments hold millisecond time gaps between membrane spikes while transmitting microsecond signals of electromagnetic vortices.
Article
Chemistry, Multidisciplinary
Jose M. Sojo-Gordillo, Gerard Gadea-Diez, David Renahy, Marc Salleras, Carolina Duque-Sierra, Pascal Vincent, Luis Fonseca, Pierre-Olivier Chapuis, Alex Morata, Severine Gomes, Albert Tarancon
Summary: A combined scanning thermal microscope and scanning electron microscope was used to characterize a suspended silicon nanowire. The thermal and mechanical properties were measured simultaneously, and the effects of the rough surface on heat dissipation and stiffness were studied.
Article
Construction & Building Technology
Jun'an Lei, Nanxiang Zheng, Xiaobao Chen, Jiefu Bi, Xirong Wu
Summary: The micro-texture of the aggregate plays a crucial role in the anti-skid performance of asphalt pavement. Sandstone exhibits the best anti-skid performance, followed by magmatic rock and limestone.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Engineering, Mechanical
Samuel Olukayode Akinwamide, Andrew Venter, Ojo Jeremiah Akinribide, Bukola Joseph Babalola, Anthony Andrews, Peter Apata Olubambi
Summary: This study investigates the effect of residual stress on the corrosion behavior of 2205 duplex stainless steel in a chloride environment, and demonstrates its excellent corrosion resistance and potential to replace conventional alloys.
ENGINEERING FAILURE ANALYSIS
(2022)
Article
Polymer Science
Rene Daher, Ivo Krejci, Enrico di Bella, Laurine Marger
Summary: The study evaluated the use of digital optical microscopy (DOM) for analyzing marginal adaptation of dental adhesive interfaces, comparing it with scanning electron microscopy (SEM). The results showed no statistically significant difference between DOM and SEM analysis, and DOM analysis took less time.
Article
Optics
Yingfan Xiong, Jinming Gou, Zhaohui Tang, Guangxu Xiao, Lihua Lei, Song Song, Xiao Deng, Xinbin Cheng
Summary: In this study, a self-traceable two-dimensional nano-grating was innovatively developed as a characterizer for scanning tips. The periodic stability of the grating was analyzed and the lateral distortion of atomic force microscopy was corrected, leading to accurate characterization of angle information for the scanning tip.
Editorial Material
Medicine, General & Internal
Winfred W. Williams, James F. Markmann
Summary: Thousands of people in the United States die each year while awaiting lifesaving liver transplantation due to a lack of donor organs. This crisis has fueled interest in expanding the organ supply, including the use of organs from expanded-criteria donation.
NEW ENGLAND JOURNAL OF MEDICINE
(2021)
Article
Chemistry, Multidisciplinary
Huaying Lin, Shixiang Tian, Anjun Jiao, Zuoyong Cao, Kai Song, Yihuai Zou
Summary: Understanding the pore heterogeneity of tectonic coal and primary-structure coal is crucial for predicting and preventing tectonic coal. Experimental results show that tectonic coal has higher aliphatic functional groups and hydrogen content than aromatic structural groups, with a wider pore size distribution and higher specific surface area.
Article
Materials Science, Multidisciplinary
Teng-Jan Chang, Hsing-Yang Chen, Chin- Wang, Hsin-Chih Lin, Chen-Feng Hsu, Jer-Fu Wang, Chih-Hung Nien, Chih-Sheng Chang, Iuliana P. Radu, Miin-Jang Chen
Summary: In recent years, the interest in Hf0.5Zr0.5O2 (HZO) thin films has grown due to their well-behaved ferroelectricity and high compatibility with semiconductor integrated circuit technology. The phase transformation and wake-up effect in HZO were identified using the precession electron diffraction (PED) phase mapping technique. The absence of the tetragonal (t-) phase is responsible for the wake-up-free property in the ferroelectric HZO thin film. The wake-up-free and pronounced ferroelectricity of the nanoscale HZO thin film in this study may have practical implications for various ferroelectric applications.
Article
Physics, Applied
Amin Reihani, Shen Yan, Yuxuan Luan, Rohith Mittapally, Edgar Meyhofer, Pramod Reddy
Summary: This study presents a custom-fabricated scanning thermal probe (STP) that can accurately measure the temperature of microdevices at elevated temperatures. By introducing a modulated heat input and analyzing the different components of the STP temperature, the tip-to-sample thermal resistance and microdevice surface temperature can be simultaneously deduced.
APPLIED PHYSICS LETTERS
(2021)
Article
Physics, Multidisciplinary
T. Sagesser, R. Matt, R. Oswald, J. P. Home
NEW JOURNAL OF PHYSICS
(2020)
Article
Physics, Multidisciplinary
C. Fluhmann, J. P. Home
PHYSICAL REVIEW LETTERS
(2020)
Article
Physics, Multidisciplinary
S. Jain, J. Alonso, M. Grau, J. P. Home
Article
Multidisciplinary Sciences
Karan K. Mehta, Chi Zhang, Maciej Malinowski, Thanh-Long Nguyen, Martin Stadler, Jonathan P. Home
Article
Physics, Multidisciplinary
Florentin Reiter, Thanh Long Nguyen, Jonathan P. Home, Susanne F. Yelin
PHYSICAL REVIEW LETTERS
(2020)
Article
Quantum Science & Technology
Chiara Decaroli, Roland Matt, Robin Oswald, Christopher Axline, Maryse Ernzer, Jeremy Flannery, Simon Ragg, Jonathan P. Home
Summary: This paper describes the implementation of a three-dimensional Paul ion trap with 142 dedicated electrodes for defining multiple potential wells and holding ion strings. Time-varying potentials allow for transport and re-configuration of ion strings, and initial testing includes measurements of heating rates and junction transport.
QUANTUM SCIENCE AND TECHNOLOGY
(2021)
Article
Physics, Multidisciplinary
Brennan de Neeve, Thanh-Long Nguyen, Tanja Behrle, Jonathan P. Home
Summary: Stabilization of logical qubits encoded using quantum error correction is essential for reliable quantum computing. Implementing encoding with quantum oscillators such as GKP codes allows for correction of small displacement errors with a single physical entity. By introducing a dissipative map designed for finite GKP codes and demonstrating an extension in coherence time using both square and hexagonal GKP codes, the lifetime of qubits encoded in the motion of a trapped ion has been extended.
Article
Physics, Multidisciplinary
Ivan Rojkov, David Layden, Paola Cappellaro, Jonathan Home, Florentin Reiter
Summary: The sensitivity of quantum sensors is limited by decoherence. Quantum error correction (QEC) can enhance sensitivity by suppressing decoherence but causes a bias in the sensor's output in realistic settings. Failure to account for this bias can systematically reduce the sensor's performance in experiments and provide misleading values for the minimum detectable signal in theory. The analysis focuses on the experimentally motivated setting of continuous-time QEC, demonstrating how to address and mitigate this effect and highlighting potential incorrect results.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
M. Malinowski, C. Zhang, V Negnevitsky, I Rojkov, F. Reiter, T-L Nguyen, M. Stadler, D. Kienzler, K. K. Mehta, J. P. Home
Summary: This study proposes and implements a novel scheme for converting two qubits into a singlet Bell state through dissipative pumping. The method utilizes collective optical pumping to an excited level, allowing for deterministic entanglement of two trapped ions. The results show that a high fidelity singlet state can be achieved within a certain number of pumping cycles.
PHYSICAL REVIEW LETTERS
(2022)
Article
Quantum Science & Technology
S. Auchter, C. Axline, C. Decaroli, M. Valentini, L. Purwin, R. Oswald, R. Matt, E. Aschauer, Y. Colombe, P. Holz, T. Monz, R. Blatt, P. Schindler, C. Roessler, J. Home
Summary: This study presents a highly scalable approach for fabricating a new generation of 3D ion traps using stacked wafers. The traps achieved a significant trapping depth and were characterized and evaluated comprehensively. This fabrication method has the potential to advance trapped-ion quantum computing.
QUANTUM SCIENCE AND TECHNOLOGY
(2022)
Article
Physics, Multidisciplinary
Chi Zhang, Karan K. Mehta, Jonathan P. Home
Summary: This paper describes the design of a surface-electrode ion trap junction, which is an essential component for large-scale ion trap arrays. The electrodes are designed using a bi-objective optimization method to maintain the total pseudo-potential curvature while minimizing the axial pseudo-potential gradient along the ion transport path. Integrated optics are implemented on each arm of the X-junction trap to facilitate laser beam delivery for parallel operations in multiple trap zones. The layout of the trap chip for commercial foundry fabrication is presented. This work suggests ways to improve ion trap junction performance in scalable implementations and contributes to modular trapped-ion quantum computing in interconnected two-dimensional arrays.
NEW JOURNAL OF PHYSICS
(2022)
Article
Physics, Applied
Leonardo Massai, Tom Schatteburg, Jonathan P. P. Home, Karan K. K. Mehta
Summary: The article introduces a method for generating highly pure circular polarization fields using waveguide microring resonators, which achieve high circular polarization purity by taking advantage of the symmetries of the structure and radiated modes, and directly utilizing both transverse and longitudinal field components of the guided modes. This is of great significance for achieving high-fidelity control and measurement in atomic quantum systems.
APPLIED PHYSICS LETTERS
(2022)
Article
Physics, Multidisciplinary
Alfredo Ricci Vasquez, Carmelo Mordini, Chloe Verniere, Martin Stadler, Maciej Malinowski, Chi Zhang, Daniel Kienzler, Karan K. Mehta, Jonathan P. Home
Summary: Using a single calcium ion trapped in a surface-electrode trap, the interaction of electric quadrupole transitions with a passively phase-stable optical standing wave field sourced by photonics integrated within the trap is studied. The optical fields are characterized through spatial mapping of the Rabi frequencies of both carrier and motional sideband transitions as well as ac Stark shifts. The measurements demonstrate the ability to engineer favorable combinations of sideband and carrier Rabi frequency as well as ac Stark shifts for specific tasks in quantum state control and metrology.
PHYSICAL REVIEW LETTERS
(2023)
Article
Instruments & Instrumentation
Oliver Wipfli, Henry Fernandes Passagem, Christoph Fischer, Matt Grau, Jonathan P. Home
Summary: This paper reports the realization of a hemispherical optical cavity that has a finesse of F = 13,000 and can sustain inter-cavity powers of 10 kW. The cavity was designed with an integrated radio-frequency Paul trap to combine optical and radio-frequency trapping. The system's design and operation, including low-vibration mounting, locking, and thermal effects at high powers are described. Observations made over a year show a repeatable shift between the ion trap center and the cavity mode.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Physics, Multidisciplinary
Florentin Reiter, Florian Lange, Shreyans Jain, Matt Grau, Jonathan P. Home, Zala Lenarcic
Summary: The concept of generalized Gibbs ensembles (GGEs) describes steady states of integrable models and can also be stabilized in nearly integrable quantum systems. A weakly dissipative dynamics driving towards a steady-state GGE has been proposed and is implementable in systems of trapped ions. By engineering the desired dissipation through couplings, detection of GGEs in open systems and quantum simulation of driven-dissipative many-body problems become feasible.
PHYSICAL REVIEW RESEARCH
(2021)
