Quadrupolar induced suppression of nuclear spin bath fluctuations in self-assembled quantum dots

Abstract

Decoherence in quantum logic gates (qubits) due to interaction with the surrounding environment is a major obstacle to the practical realization of quantum information technologies. For solid state electron-spin qubits the interaction with nuclear spins is the main problem. One particular, neradicable source of electron decoherence arises from decoherence of the nuclear spin bath, driven by nuclear-nuclear dipolar interactions. Due to its many-body nature nuclear decoherence is difficult to predict, especially for an important class of strained nanostructures where nuclear quadrupolar effects have a significant but largely unknown impact. Here we report direct measurement of nuclear spin bath coherence in individual strained InGaAs/GaAs quantum dots: nuclear spin-echo coherence times in the range T2~1.2 - 4.5 ms are found. Based on these T2 values we demonstrate that quadrupolar interactions make nuclear fluctuations in strained quantum dots much slower compared to lattice matched GaAs/AlGaAs structures. Such fluctuation suppression is particularly strong for arsenic nuclei due to the effect of atomic disorder of gallium and indium alloying. Our findings demonstrate that quadrupolar effects can help to solve the long-standing challenge of designing a scalable hardware for quantum computation: III-V semiconductor spin-qubits can be engineered to have a noise-free nuclear spin bath (previously achievable only in nuclear spin-0 semiconductors, where qubit network interconnection and scaling is challenging).

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Cited by in corpus (16)

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• Nuclear spin diffusion in the central spin system of a GaAs/AlGaAs quantum dot
• On the impact of strain on the electronic properties of InAs/GaSb quantum well systems
• Unveiling the electron-nuclear spin dynamics in an n-doped InGaAs epilayer by spin noise spectroscopy
• A many-body singlet prepared by a central spin qubit
• Time-crystalline behavior in central-spin models with Heisenberg interactions
• Wavelet-resolved coherence beats in the Overhauser field of a thermal nuclear spin ensemble
• Quantum non-demolition measurement of an electron spin qubit through its low-energy many-body spin environment
• Noise suppression and long-range exchange coupling for gallium arsenide spin qubits
• Dissipative evolution of a two-level system through a geometry-based classical mapping
• Dynamical decoupling of interacting spins through group factorization
• Noise-resistant quantum memory enabled by Hamiltonian engineering
• Direct high resolution resonant Raman scattering measurements of InAs quantum dot dynamic nuclear spin polarization states
• Quantifying electron-nuclear spin entanglement dynamics in central-spin systems using one-tangles
• Dynamical nuclear spin polarization in a quantum dot with an electron spin driven by electric dipole spin resonance