We investigate hole spin relaxation in the single- and multihole regime in a 2 × 2 germanium quantum dot array. We find spin relaxation times as high as 32 and 1.2 ms for quantum dots with single- and five-hole occupations, respectively, setting benchmarks for spin relaxation times for hole quantum dots. Furthermore, we investigate qubit addressability and electric field sensitivity by measuring resonance frequency dependence of each qubit on gate voltages. We can tune the resonance frequency over a large range for both single and multihole qubits, while simultaneously finding that the resonance frequencies are only weakly dependent on neighboring gates. In particular, the five-hole qubit resonance frequency is more than 20 times as sensitive to its corresponding plunger gate. Excellent individual qubit tunability and long spin relaxation times make holes in germanium promising for addressable and high-fidelity spin qubits in dense two-dimensional quantum dot arrays for large-scale quantum information.
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http://dx.doi.org/10.1021/acs.nanolett.0c02589 | DOI Listing |
Sensors (Basel)
January 2025
Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
Optically pumped magnetometers (OPMs) functioning in the spin-exchange relaxation-free (SERF) regime have emerged as attractive options for measuring weak magnetic fields, owing to their portability and remarkable sensitivity. The operation of SERF-OPM critically relies on the ambient magnetic field; thus, a magnetic field compensation device is commonly employed to mitigate the ambient magnetic field to near zero. Nonetheless, the bias of the OPM may influence the compensation impact, a subject that remains unexamined.
View Article and Find Full Text PDFMolecules
January 2025
Department of Engineering Science, The University of Electro-Communications, Chofu 182-8585, Tokyo, Japan.
A new compound [Y(sq)(HO)] (Y-sq; sq = squarate (CO)) was prepared and structurally characterized. Since the RE-sq family (RE = Y, Dy, Yb, Lu) gave isostructural crystals, the objective of this study is to explore the effects of diamagnetic dilution on the SIM behavior through systematic investigation and comparison of diamagnetically diluted and undiluted forms. The 1%-Diluted Dy compounds, Dy@Y-sq and Dy@Lu-sq, showed AC magnetic susceptibility peaks without any DC bias field (), whereas undiluted Dy-sq showed no AC out-of-phase response under the same conditions.
View Article and Find Full Text PDFFoods
January 2025
Heyuan Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Heyuan 517000, China.
This study investigated the impact of glycerol monooleate (MO) at varying levels (0.3%, 0.6%, 0.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Chemistry, HKU-CAS Joint Laboratory on New Materials and Shanghai-Hong Kong Joint Laboratory on Chemical Synthesis, The University of Hong Kong, Hong Kong, China.
High-spin carbon-based polyradicals exhibit significant potential for applications in quantum information storage and sensing; however, their practical application is hampered by limited structural diversity and chemical instability. Here, we report a straightforward synthetic and isolation method for synthesizing a nonalternant nanographene (1) with a triplet ground state. Moving beyond the classic m-xylylene scaffold for high-spin organic molecules, seven-five-seven (7-5-7)-membered rings are introduced to create stable high-spin diradicals with half-lives (t) as long as 101 days.
View Article and Find Full Text PDFJ Magn Reson
January 2025
Center for Magnetic Resonance Research, University of Minnesota, 2021 6th Street SE, Minneapolis, MN 55455, USA. Electronic address:
In this work the effect of the geometric phase on time evolution of the density matrix was evaluated during nonadiabatic radiofrequency (RF) pulses with Sine amplitude modulation (AM) and Cosine frequency modulation (FM) functions of the RAFF (Relaxations Along a Fictitious Field) family, and the polarization between two energy level ½ spin system coupled by dipolar interaction was evaluated during the application of RF irradiation. The dependencies of the diagonal density matrix elements and the polarization on the rotational correlation times and the time during RF pulses were evaluated. The general treatment of the density matrix elements along with the polarization generated during RF pulses was unavailable thus far, and for the first time was here derived for the nonadiabatic case of the RAFF pulses.
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