A dressed singlet-triplet qubit in germanium

Fuente: arXiv
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Main Authors: Tsoukalas, Konstantinos, von Lüpke, Uwe, Orekhov, Alexei, Hetényi, Bence, Seidler, Inga, Sommer, Lisa, Kelly, Eoin G., Massai, Leonardo, Aldeghi, Michele, Pita-Vidal, Marta, Hendrickx, Nico W., Bedell, Stephen W., Paredes, Stephan, Schupp, Felix J., Mergenthaler, Matthias, Salis, Gian, Fuhrer, Andreas, Harvey-Collard, Patrick
Format: Preprint
Published: 2025
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author Tsoukalas, Konstantinos
von Lüpke, Uwe
Orekhov, Alexei
Hetényi, Bence
Seidler, Inga
Sommer, Lisa
Kelly, Eoin G.
Massai, Leonardo
Aldeghi, Michele
Pita-Vidal, Marta
Hendrickx, Nico W.
Bedell, Stephen W.
Paredes, Stephan
Schupp, Felix J.
Mergenthaler, Matthias
Salis, Gian
Fuhrer, Andreas
Harvey-Collard, Patrick
author_facet Tsoukalas, Konstantinos
von Lüpke, Uwe
Orekhov, Alexei
Hetényi, Bence
Seidler, Inga
Sommer, Lisa
Kelly, Eoin G.
Massai, Leonardo
Aldeghi, Michele
Pita-Vidal, Marta
Hendrickx, Nico W.
Bedell, Stephen W.
Paredes, Stephan
Schupp, Felix J.
Mergenthaler, Matthias
Salis, Gian
Fuhrer, Andreas
Harvey-Collard, Patrick
contents In semiconductor hole spin qubits, low magnetic field ($B$) operation extends the coherence time ($T_\mathrm{2}^*$) 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 $T_\mathrm{2}^*=1.9\,μ$s. Moreover, by applying the resonant drive continuously, we realize a dressed ST qubit with a tenfold increase in coherence time ($T_\mathrm{2ρ}^*=20.3\,μ$s). Frequency modulation of the driving signal enables universal control, with an average gate fidelity of $99.63\%$. Our results demonstrate the potential for extending coherence times while preserving high-fidelity control of germanium-based ST qubits, paving the way for more efficient operations in semiconductor-based quantum processors.
format Preprint
id arxiv_https___arxiv_org_abs_2501_14627
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle A dressed singlet-triplet qubit in germanium
Tsoukalas, Konstantinos
von Lüpke, Uwe
Orekhov, Alexei
Hetényi, Bence
Seidler, Inga
Sommer, Lisa
Kelly, Eoin G.
Massai, Leonardo
Aldeghi, Michele
Pita-Vidal, Marta
Hendrickx, Nico W.
Bedell, Stephen W.
Paredes, Stephan
Schupp, Felix J.
Mergenthaler, Matthias
Salis, Gian
Fuhrer, Andreas
Harvey-Collard, Patrick
Mesoscale and Nanoscale Physics
Quantum Physics
In semiconductor hole spin qubits, low magnetic field ($B$) operation extends the coherence time ($T_\mathrm{2}^*$) 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 $T_\mathrm{2}^*=1.9\,μ$s. Moreover, by applying the resonant drive continuously, we realize a dressed ST qubit with a tenfold increase in coherence time ($T_\mathrm{2ρ}^*=20.3\,μ$s). Frequency modulation of the driving signal enables universal control, with an average gate fidelity of $99.63\%$. Our results demonstrate the potential for extending coherence times while preserving high-fidelity control of germanium-based ST qubits, paving the way for more efficient operations in semiconductor-based quantum processors.
title A dressed singlet-triplet qubit in germanium
topic Mesoscale and Nanoscale Physics
Quantum Physics
url https://arxiv.org/abs/2501.14627