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Exchange anisotropies in microwave-driven singlet-triplet qubits
Jaime Saez-Mollejo1, Daniel Jirovec2,3, Yona Schell2
1Institute of Science and Technology Austria, Klosterneuburg, Austria. jaime.saezmollejo@ist.ac.at.
Nature Communications
|April 24, 2025
Summary
Hole spin qubits in germanium demonstrate tunable spin anisotropies for scalable quantum processors. Researchers achieved coherence times over 3 μs, paving the way for advanced quantum computing applications.
Area of Science:
- Quantum Computing
- Semiconductor Physics
- Spintronics
Background:
- Hole spin qubits are crucial for semiconducting quantum processors due to their efficient all-electric operations.
- Spin-orbit interaction in these qubits leads to site-dependent energies and anisotropies, which can impact scalability.
Purpose of the Study:
- To investigate spin anisotropies in microwave-driven singlet-triplet qubits in planar germanium.
- To explore the electrical tunability of these anisotropies and their effect on qubit performance.
Main Methods:
- Fabrication and characterization of planar germanium-based singlet-triplet qubits.
- Application of in-plane and out-of-plane magnetic fields to study spin anisotropy.
- Measurement of qubit coherence times under different magnetic field configurations.
Main Results:
- Demonstrated largely anisotropic and electrically tunable spin responses for in-plane magnetic fields.
- Achieved qubit coherence times exceeding 3 μs with in-plane fields.
- Observed an isotropic response for out-of-plane fields, with coherence times of 400 ns despite nuclear spin interactions.
Conclusions:
- Spin anisotropies in germanium hole qubits are significant and electrically tunable, offering a pathway to harness them for scalable quantum processors.
- The findings provide a valuable tool for investigating and controlling spin anisotropies in 2D devices.
- This research advances the development of robust and scalable quantum computing architectures.
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