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Among many modulation methods, strain engineering is often chosen for nanomaterials to produce tunable band gaps continuously. Inspired by the recently reported two-dimensional material PC3, we explore the tuning of strain on the spin-dependent transport properties of PC3 nanoribbons using the first-principle approach. Surprisingly, strain regulation achieves uninterrupted completely dual-spin polarization over a wide energy range near EF. Analysis reveals that the peculiar transmission spectra arise from the interesting evolution of the band structure, in which strain induces bands to shift and broaden/flatten. This results in triggering the transition of PC3NRs from bandgap-tunable bipolar magnetic semiconductors to spin-gapless semiconductors to ferromagnetic metals or half-metal magnets. Their unique performance demonstrates great potential in spintronics, and our study is expected to provide ideas and theoretical support for the design and application of novel PC3-based spintronic devices in the future.
RESUMO
Correction for 'Rich magnetic phase transitions and completely dual-spin polarization of zigzag PC3 nanoribbons under uniaxial strain' by Hui-Min Ni et al., Phys. Chem. Chem. Phys., 2023, https://doi.org/10.1039/d2cp05066h.
RESUMO
The unique edge states of the zigzag ß-SiC7 nanoribbons aroused our attention, and therefore, based on first-principles calculations, we investigated their spin-dependent electronic transport properties by constructing controllable defects to modulate these special edge states. Interestingly, by introducing rectangular edge defects in the SiSi and SiC edge-terminated systems, not only the spin-unpolarized is successfully converted to completely spin-polarized, but also the direction of polarization can be switched, thus enabling a dual spin filter. The analyses further reveal that the two transmission channels with opposite spins are spatially separated and that the transmission eigenstates are highly concentrated at the relative edges. The specific edge defect introduced only suppresses the transmission channel at the same edge but reserves the transmission channel at the other edge. In addition, for the CSi and CC edge-terminated systems, an additional spin-down band exists due to spin splitting in the spin-up band at EF, so that besides the original spatially separated two spin-opposite channels, an extra spin channel is distributed at the upper edge, resulting in unidirectional fully spin-polarized transport. The peculiar spatially separated edge states and excellent spin filtering properties could open up further possibilities for ß-SiC7-based electronic devices in spintronics applications.
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Compared with traditional magnetic approaches, electrical modulation of spin-polarized current can greatly reduce the energy consumption and scale of nanodevices and improve their operating speed, which has become a promising research field in spintronics. Motivated by the latest reported novel two-dimensional material ß-SiC7, we employ first-principles calculations to investigate its spin-dependent electron transport with diverse edge configurations. By introducing a gate voltage, the three-terminal device can not only switch between spin-unpolarized and fully spin-polarized states, but also easily change the polarization direction, behaving as an excellent electrically modulated reversible dual-spin filter. Surprisingly, an arbitrary proportion of spin-up and spin-down electron numbers is achieved, enabling precise control of spin polarization. Analysis reveals that it is attributed to the peculiar transmission spectrum, where two broad peaks with opposite spins are located around the Fermi level and respond differently to gate voltage. They belong to the spatially separated edge states originating from the p orbitals of the edge atoms. This feature is robust to different edge configurations of ß-SiC7 nanoribbons, indicating that this may be an intrinsic property of such systems, showing great potential for applications.
RESUMO
Introduction Administering intravenous thrombolytic therapy within 60 minutes on arrival in any healthcare facility is challenging, especially when done by Emergency Medicine Physicians (EMP) via telemedicine in centres without onsite neurology cover. Prior quality improvement interventions have improved median Door-to-Needle (DTN) timings in our centre; however, it still falls short of the DTN target of 60 minutes. Methods Various quality improvement interventions were implemented over four months by a multi-disciplinary telestroke workgroup led by EMPs to improve DTN timings for patients presenting with acute ischaemic strokes. A retrospective observational study was conducted to review if these interventions resulted in an improvement in DTN timings while keeping the rates of stroke mimics given thrombolytic therapy, haemorrhagic conversions and 30-day mortality rates low. Results A total of 279 patients were evaluated. Median DTN timings significantly improved from 71.0 minutes pre-intervention to 62.0 minutes post-intervention (p=0.012). Correspondingly, the proportion of patients with DTN ≤ 60 minutes increased from 31.7% pre-intervention to 47.0% post-intervention, giving an odds ratio of 1.91 (95% CI 1.17 - 3.11, p=0.009). There were no significant differences found in the rates of stroke mimics, haemorrhagic conversions and 30-day mortality pre and post-intervention. Conclusion The implementation of EMP led to systemic quality improvement interventions is associated with improved DTN timings without compromising clinical quality outcome measures like haemorrhagic conversion rates and 30-day mortality rates. EMPs, with a broad knowledge base and familiarity, interacting with various specialities and co-ordinating care, are uniquely suited in this role to drive change. More work in the public health sector would also have to be done to improve the population's response to acute stroke symptoms.