Low-frequency spin qubit detuning noise in highly purified ${}^{28}$Si/SiGe

Abstract

The manipulation fidelity of a single electron qubit gate-confined in a ${}^{28}$Si/SiGe quantum dot has recently been drastically improved by nuclear isotope purification. Here, we identify the dominant source for low-frequency qubit detuning noise in a device with an embedded nanomagnet, a remaining ${}^{29}$Si concentration of only 60ppm in the strained ${}^{28}$Si quantum well layer and a spin echo decay time $T_2^{\text{echo}}=128\mu$s. The power spectral density (PSD) of the charge noise explains both the observed transition of a $1/f^2$- to a $1/f$-dependence of the detuning noise PSD as well as the observation of a decreasing time-ensemble spin dephasing time from $T_2^{\ast }\approx 20\mu$s with increasing measurement time over several hours. Despite their strong hyperfine contact interaction, the few ${}^{73}$Ge nuclei overlapping with the quantum dot in the barrier do not limit $T_2^{\ast }$, as their dynamics is frozen on a few hours measurement scale. We conclude that charge noise and the design of the gradient magnetic field is the key to further improve the qubit fidelity.

References in corpus (33)

• Spins in few-electron quantum dots
• Driven coherent oscillations of a single electron spin in a quantum dot
• Silicon Quantum Electronics
• An addressable quantum dot qubit with fault-tolerant control fidelity
• A Two Qubit Logic Gate in Silicon
• A >99.9%-fidelity quantum-dot spin qubit with coherence limited by charge noise
• A programmable two-qubit quantum processor in silicon
• Storing quantum information for 30 seconds in a nanoelectronic device
• Electrically driven single electron spin resonance in a slanting Zeeman field
• Quantum CNOT Gate for Spins in Silicon
• How to Enhance Dephasing Time in Superconducting Qubits
• Fidelity benchmarks for two-qubit gates in silicon
• Electrometry Using Coherent Exchange Oscillations in a Singlet-Triplet-Qubit
• Silicon qubit fidelities approaching incoherent noise limits via pulse engineering
• Electron Spin Dephasing due to Hyperfine Interactions with a Nuclear Spin Bath
• Low-frequency charge noise in Si/SiGe quantum dots
• Quantum Dot Arrays in Silicon and Germanium
• Spin lifetime and charge noise in hot silicon quantum dot qubits
• Measurement of Temporal Correlations of the Overhauser Field in a Double Quantum Dot
• Hyperfine interactions in silicon quantum dots
• Electrically Protected Valley-Orbit Qubits in Silicon
• Extending the coherence of a quantum dot hybrid qubit
• Large, tunable valley splitting and single-spin relaxation mechanisms in a Si/Si${}_x$Ge${}_{1-x}$ quantum dot
• Spectrum of the Nuclear Environment for GaAs Spin Qubits
• Quantifying error and leakage in an encoded Si/SiGe triple-dot qubit
• Single-spin qubits in isotopically enriched silicon at low magnetic field
• Dephasing of electron spin qubits due to their interaction with nuclei in quantum dots
• Controllable freezing of the nuclear spin bath in a single-atom spin qubit
• Large nuclear spin polarization in gate-defined quantum dots using a single-domain nanomagnet
• Few electron double quantum dot in an isotopically purified ${}^{28}$Si quantum well
• Characterization and Suppression of Low-frequency Noise in Si/SiGe Quantum Point Contacts and Quantum Dots
• Electrical detection of free induction decay and Hahn echoes in phosphorus doped silicon
• SiGe/Si quantum dot electron spin decoherence dependence on ${}^{73}$Ge

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