| 1. |
- Karelina, L. N., et al.
(författare)
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Scalable memory elements based on rectangular SIsFS junctions
- 2021
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 130:17
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Tidskriftsartikel (refereegranskat)abstract
- We explore the concept of the Josephson magnetic memory element based on a multilayer two-barrier SIsFS Josephson junction storing the digital state by means of the orientation of magnetization in the F-layer. A diluted PdFe alloy with 1% magnetic atoms is used as a ferromagnet (F), and a tunnel A1Ox layer (I) ensures a high voltage in the resistive state. We have studied two junctions of a rectangular shape in which two digital states are defined by the orientation of the residual F-layer magnetization set along or across the junction in the plane of the ferromagnetic barrier. Implementations of both binary and ternary logic elements are demonstrated. A scalability of rectangular memory elements is analyzed using micro-magnetic modeling.
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| 2. |
- Eremeev, S. V., et al.
(författare)
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Insight into the electronic structure of the centrosymmetric skyrmion magnet GdRu 2 Si 2
- 2023
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Ingår i: Nanoscale Advances. - 2516-0230. ; 5:23, s. 6678-6687
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Tidskriftsartikel (refereegranskat)abstract
- The discovery of a square magnetic-skyrmion lattice in GdRu2Si2, with the smallest so far found skyrmion size and without a geometrically frustrated lattice, has attracted significant attention. In this work, we present a comprehensive study of surface and bulk electronic structures of GdRu2Si2 by utilizing momentum-resolved photoemission (ARPES) measurements and first-principles calculations. We show how the electronic structure evolves during the antiferromagnetic transition when a peculiar helical order of 4f magnetic moments within the Gd layers sets in. A nice agreement of the ARPES-derived electronic structure with the calculated one has allowed us to characterize the features of the Fermi surface (FS), unveil the nested region along kz at the corner of the 3D FS, and reveal their orbital compositions. Our findings suggest that the Ruderman-Kittel-Kasuya-Yosida interaction plays a decisive role in stabilizing the spiral-like order of Gd 4f moments responsible for the skyrmion physics in GdRu2Si2. Our results provide a deeper understanding of electronic and magnetic properties of this material, which is crucial for predicting and developing novel skyrmion-based systems.
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| 3. |
- Golod, Taras, et al.
(författare)
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Reconfigurable Josephson Phase Shifter
- 2021
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Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 21:12, s. 5240-5246
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Tidskriftsartikel (refereegranskat)abstract
- Phase shifter is one of the key elements of quantum electronics. In order to facilitate operation and avoid decoherence, it has to be reconfigurable, persistent, and nondissipative. In this work, we demonstrate prototypes of such devices in which a Josephson phase shift is generated by coreless superconducting vortices. The smallness of the vortex allows a broad-range tunability by nanoscale manipulation of vortices in a micron-size array of vortex traps. We show that a phase shift in a device containing just a few vortex traps can be reconfigured between a large number of quantized states in a broad [−3π, +3π] range.
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| 4. |
- Grebenchuk, Sergey Yu, et al.
(författare)
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Observation of interacting Josephson vortex chains by magnetic force microscopy
- 2020
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Ingår i: Physical Review Research. - 2643-1564. ; 2:2
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Tidskriftsartikel (refereegranskat)abstract
- The ability to control Josephson vortices is instrumental for development of superconducting cryoelectronics. However, direct visualization of multivortex states in Josephson junctions is a challenging task. Here, we employ a magnetic force microscopy (MFM) for the analysis of planar Josephson junctions. We observe a specific MFM response, seen as a chain of small rings. By changing the applied field, we show that the number of rings is equal to the number of flux quanta in the junction. Therefore, each ring represents an individual vortex in a one-dimensional vortex chain within the junction. Our observation demonstrates that the MFM technique can be used for visualization of Josephson vortices and for probing their spatial configurations and mutual interaction.
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| 5. |
- Hartley, Philippa, et al.
(författare)
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SKA Science Data Challenge 2: analysis and results
- 2023
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Ingår i: Monthly Notices of the Royal Astronomical Society. - 0035-8711 .- 1365-2966. ; 523:2, s. 1967-1993
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Tidskriftsartikel (refereegranskat)abstract
- The Square Kilometre Array Observatory (SKAO) will explore the radio sky to new depths in order to conduct transformational science. SKAO data products made available to astronomers will be correspondingly large and complex, requiring the application of advanced analysis techniques to extract key science findings. To this end, SKAO is conducting a series of Science Data Challenges, each designed to familiarize the scientific community with SKAO data and to drive the development of new analysis techniques. We present the results from Science Data Challenge 2 (SDC2), which invited participants to find and characterize 233 245 neutral hydrogen (H i) sources in a simulated data product representing a 2000 h SKA-Mid spectral line observation from redshifts 0.25-0.5. Through the generous support of eight international supercomputing facilities, participants were able to undertake the Challenge using dedicated computational resources. Alongside the main challenge, 'reproducibility awards' were made in recognition of those pipelines which demonstrated Open Science best practice. The Challenge saw over 100 participants develop a range of new and existing techniques, with results that highlight the strengths of multidisciplinary and collaborative effort. The winning strategy - which combined predictions from two independent machine learning techniques to yield a 20 per cent improvement in overall performance - underscores one of the main Challenge outcomes: that of method complementarity. It is likely that the combination of methods in a so-called ensemble approach will be key to exploiting very large astronomical data sets.
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