A dressed singlet-triplet qubit in germanium.

ABSTRACT: In semiconductor hole spin qubits, low magnetic field (B) operation extends the coherence time ( T2* ) but proportionally reduces the gate speed. In contrast, singlet-triplet (ST) qubits are primarily controlled by the exchange interaction ( J) and can thus maintain high gate speeds even at low B. However, a large J introduces a significant charge component to the qubit, rendering ST qubits more vulnerable to charge noise when driven. Here, we demonstrate a highly coherent ST hole spin qubit in germanium, operating at both low B and low J. By modulating J, we achieve resonant driving of the ST qubit, obtaining an average gate fidelity of 99.68% and a coherence time of T2*=1.9μs . Moreover, by applying the resonant drive continuously, we realize a dressed ST qubit with a tenfold increase in

SUBMITTER: Tsoukalas K 

PROVIDER: S-EPMC12820228 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature