A spin filter is a device that allows only a single spin state to pass, equivalent to a polarizing filter for a beam of light. Here, taking inspiration from shortcuts to adiabaticity, I demonstrate that the potential landscape of a typical quantum point contact can be tuned to act as a two terminal spin filter or to generate a spin-polarized beam. The effect presented is sufficiently robust that rough engineering yields a significant effect, as demonstrated by experiments on asymmetrically biased quantum point contacts in InAs quantum wells.
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http://dx.doi.org/10.1103/PhysRevLett.133.047001 | DOI Listing |
Phys Chem Chem Phys
January 2025
King Abdullah University of Science and Technology (KAUST), Physical Science and Engineering Division (PSE), Thuwal 23955-6900, Saudi Arabia.
Employing density functional theory for ground state quantum mechanical calculations and the non-equilibrium Green's function method for transport calculations, we investigate the potential of CdS, ZnS, CdZnS, and ZnCdS as tunnel barriers in magnetic tunnel junctions for spintronics. Based on the finding that the valence band edges of these semiconductors are dominated by p orbitals and the conduction band edges by s orbitals, we show that symmetry filtering of the Bloch states in magnetic tunnel junctions with Fe electrodes results in high tunneling magnetoresistances and high spin-polarized current (up to two orders of magnitude higher than in the case of the Fe/MgO/Fe magnetic tunnel junction).
View Article and Find Full Text PDFRev Sci Instrum
January 2025
Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala 695551, India.
Quantum technology exploits fragile quantum electronic phenomena whose energy scales demand ultra-low electron temperature operation. The lack of electron-phonon coupling at cryogenic temperatures makes cooling the electrons down to a few tens of millikelvin a non-trivial task, requiring extensive efforts on thermalization and filtering high-frequency noise. Existing techniques employ bulky and heavy cryogenic metal-powder filters, which prove ineffective at sub-GHz frequency regimes and unsuitable for high-density quantum circuits such as spin qubits.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Shandong Key Laboratory of Medical Physics and Image Processing & Shandong Provincial Engineering and Technical Center of Light Manipulations, School of Physics and Electronics, Shandong Normal University, Jinan 250358, China.
Modulating the electronic properties of VSiN with high Curie temperature to realize an ideal half-metal is appealing towards spintronic applications. Here, by using first-principles calculations, we propose alloying the VSiN monolayer via substitutive doping of transition metal atoms (Sc-Ni, Y-Mo) at the V site. We find that the transition metal atom (except the Ni atom) doped VSiN systems have dynamical and thermal stability.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Institute for the Application of Nuclear Energy INEP, University of Belgrade, Banatska 31b, 11080 Belgrade, Serbia.
Thyroglobulin (Tg) is a reliable marker for detecting recurrence in differentiated thyroid cancer (DTC) patients, but frequently occurring Tg antibodies (TgAbs) can hinder accurate measurement. We aimed to develop a preanalytical protocol for precise Tg detection in TgAb presence using the immunoradiometric assay (IRMA) platform. This study involved forty-five patients who underwent IRMA Tg and radioimmunoassay (RIA) TgAb measurements, including two patients monitored for recurrence and one with confirmed recurrence.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
School of Electronics and IoT, Chongqing Polytechnic University of Electronic Technology, Chongqing, China.
This study proposes a spin-valley electron beam splitter based on the inner-edge states in a topological-insulator junction, which can allocate different ratios of spin-valley current outputs. Since the inner-edge states are associated with the "nearest path selection" mechanism, this device is referred to as the interface-modulating spin-valley electron beam splitter. Additionally, two perfect spin-valley filters in similar topological-insulator junctions are established in this study.
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