Scalable qubit architecture based on holes in quantum dot molecules

Abstract

Spins confined in quantum dots are a leading candidate for solid-state quantum bits that can be coherently controlled by optical pulses. There are, however, many challenges to developing a scalable multibit information processing device based on spins in quantum dots, including the natural inhomogeneous distribution of quantum dot energy levels, the difficulty of creating all-optical spin manipulation protocols compatible with nondestructive readout, and the substantial electron-nuclear hyperfine interaction-induced decoherence. Here, we present a scalable qubit design and device architecture based on the spin states of single holes confined in a quantum dot molecule. The quantum dot molecule qubit enables a new strategy for optical coherent control with dramatically enhanced wavelength tunability. The use of hole spins allows the suppression of decoherence via hyperfine interactions and enables coherent spin rotations using Raman transitions mediated by a hole-spin-mixed optically excited state. Because the spin mixing is present only in the optically excited state, dephasing and decoherence are strongly suppressed in the ground states that define the qubits and nondestructive readout is possible. We present the qubit and device designs and analyze the wavelength tunability and fidelity of gate operations that can be implemented using this strategy. We then present experimental and theoretical progress toward implementing this design.

13 pages, 9 figures

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• Ultrafast optical control of entanglement between two quantum dot spins
• Coherent control and suppressed nuclear feedback of a single quantum dot hole qubit
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• Observation of extremely slow hole spin relaxation in self-assembled quantum dots
• Theory of Quantum Optical Control of Single Spin in a Quantum Dot
• Engineering electron and hole tunneling with asymmetric InAs quantum dot molecules
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• Giant Stark effect in the emission of single semiconductor quantum dots
• Electrically tunable g-factors in quantum dot molecular spin states
• Coherent optical control of the spin of a single hole in a quantum dot
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• Spin Fine Structure in Optically Excited Quantum Dot Molecules
• Fast spin rotations by optically controlled geometric phases in a quantum dot
• Direct Measurement of Quantum Dot Spin Dynamics using Time-Resolved Resonance Fluorescence
• Quantum dot spectroscopy using cavity QED
• Hole Spin Mixing in InAs Quantum Dot Molecules
• Photoluminescence Spectroscopy of the Molecular Biexciton in Vertically Stacked Quantum Dot Pairs
• Fast high fidelity hole spin initialization in a single InGaAs quantum dot
• Tuning the exciton g-factor in single InAs/InP quantum dots
• Electric g Tensor Control and Spin Echo of a Hole-Spin Qubit in a Quantum Dot Molecule

Cited by in corpus (29)

• Recent advances in hole-spin qubits
• Thermal entanglement and correlated coherence in two coupled double quantum dots systems
• Electrically-tunable hole g-factor of an optically-active quantum dot for fast spin rotations
• Two Coupled Double Quantum Dots Systems as an working substance for Heat Machines
• Electron states in a double quantum dot with broken axial symmetry
• Strong Hyperfine-Induced Modulation of an Optically-Driven Hole Spin in an InAs Quantum Dot
• Deterministic generation of entangled photonic cluster states from quantum dot molecules
• Coulomb interaction signatures in self-assembled lateral quantum dot molecules
• All-optical controlled phase gate in quantum dot molecules
• All electrically controlled quantum gates for single heavy hole spin qubits
• Avoiding leakage and errors caused by unwanted transitions in Lambda systems
• Theory of electrons, holes and excitons in GaAs polytype quantum dots
• Symmetry induced hole-spin mixing in quantum dot molecules
• Design of a 4-electrode optical device for application of vector electric fields to self-assembled quantum dot complexes
• Asymmetric $g$ tensor in low-symmetry two-dimensional hole systems
• Optically Loaded Semiconductor Quantum Memory Register
• Tunneling-related electron spin relaxation in self-assembled quantum-dot molecules
• Entanglement Dynamics of Molecular Exciton States in Coupled Quantum Dots
• Incorporation of random alloy GaBi${}_x$As${}_{1-x}$ barriers in InAs quantum dot molecules (I): energy levels and confined hole states
• Excitonic entanglement of protected states in quantum dot molecules
• Time-bin entanglement in the deterministic generation of linear photonic cluster states
• Spin-orbit-induced hole spin relaxation in a quantum dot molecule: the effect of $s$-$p$ coupling
• The impact of hole $g$-factor anisotropy on spin-photon entanglement generation with InGaAs quantum dots
• Network structure and dynamics of effective models of non-equilibrium quantum transport
• Gate-based protocol simulations for quantum repeaters using quantum-dot molecules in switchable electric fields
• Passive stabilization of hole spin qubit using optical Stark effect
• Trions Stimulate Electronic Coupling in Colloidal Quantum Dot Molecules
• Charging of a Single InAs QD with Electrically-Injected Holes using a Lateral Electric Field
• Incorporation of random alloy GaBi${}_x$As${}_{1-x}$ barriers in InAs quantum dot molecules: alloy strain and orbital effects towards enhanced tunneling