Hybrid superconductor-semiconductor devices made from self-assembled SiGe nanocrystals on silicon

Abstract

The epitaxial growth of germanium on silicon leads to the self-assembly of SiGe nanocrystals via a process that allows the size, composition and position of the nanocrystals to be controlled. This level of control, combined with an inherent compatibility with silicon technology, could prove useful in nanoelectronic applications. Here we report the confinement of holes in quantum-dot devices made by directly contacting individual SiGe nanocrystals with aluminium electrodes, and the production of hybrid superconductorsemiconductor devices, such as resonant supercurrent transistors, when the dot is strongly coupled to the electrodes. Charge transport measurements on weakly coupled quantum dots reveal discrete energy spectra, with the confined hole states displaying anisotropic gyromagnetic factors and strong spin-orbit coupling strength with pronounced gate-voltage and magnetic-field dependence.

35 pages, 6 figures

References in corpus (29)

• Spins in few-electron quantum dots
• Coherent control of a single electron spin with electric fields
• Supercurrent reversal in quantum dots
• Quantum supercurrent transistors in carbon nanotubes
• Electric Dipole Induced Spin Resonance in Quantum Dots
• Gate-Voltage Studies of Discrete Electronic States in Al Nanoparticles
• Double quantum dot with integrated charge sensor based on Ge/Si heterostructure nanowires
• Quantum phase transition in a single-molecule quantum dot
• Ge/Si nanowire mesoscopic Josephson junctions
• Direct Measurement of the Spin-Orbit Interaction in a Two-Electron InAs Nanowire Quantum Dot
• Electron Cotunneling in a Semiconductor Quantum Dot
• Electric-field controlled spin reversal in a quantum dot with ferromagnetic contacts
• Anomalous Josephson current through a spin-orbit coupled quantum dot
• Multiple Andreev Reflections in a Carbon Nanotube Quantum Dot
• Superconductivity in a single C60 transistor
• Giant fluctuations and gate control of the g-factor in InAs Nanowire Quantum Dots
• Kondo Universal Scaling for a Quantum Dot Coupled to Superconducting Leads
• Charge sensing and controllable tunnel coupling in a Si/SiGe double quantum dot
• Ballistic Spin Resonance
• Large anisotropy of spin-orbit interaction in a single InAs self-assembled quantum dot
• Spin relaxation at the singlet-triplet crossing in a quantum dot
• Kondo effect in a semiconductor quantum dot coupled to ferromagnetic electrodes
• Magnetic-field-induced singularities in spin dependent tunneling through InAs quantum dots
• Superconductivity-enhanced bias spectroscopy in carbon nanotube quantum dots
• Studies of spin-orbit scattering in noble-metal nanoparticles using energy level tunneling spectroscopy
• Resonant Josephson current through a quantum dot
• Giant anisotropy of Zeeman splitting of quantum confined acceptors in Si/Ge
• Lifetime measurements (T1) of electron spins in Si/SiGe quantum dots
• Single hole transistor in a p-Si/SiGe quantum well

Cited by in corpus (61)

• Silicon Quantum Electronics
• Semiconductor Spin Qubits
• Prospects for Spin-Based Quantum Computing
• The germanium quantum information route
• Ge hole spin qubit
• Spin Relaxation in Ge/Si Core-Shell Nanowire Qubits
• Electrical control over single hole spins in nanowire quantum dots
• Gate-controlled quantum dots and superconductivity in planar germanium
• Direct Rashba spin-orbit interaction in Si and Ge nanowires with different growth directions
• Anomalous Josephson current, incipient time-reversal symmetry breaking, and Majorana bound states in interacting multi-level dots
• Heavy hole states in Germanium hut wires
• Parity-conserving Cooper-pair transport and ideal superconducting diode in planar Germanium
• Large anisotropy of spin-orbit interaction in a single InAs self-assembled quantum dot
• Light effective hole mass in undoped Ge/SiGe quantum wells
• Electrically Tunable Macroscopic Quantum Tunneling in a Graphene-based Josephson Junction
• Universal transport signatures in two-electron molecular quantum dots: gate-tunable Hund's rule, underscreened Kondo effect and quantum phase transitions
• Tunable g factor and phonon-mediated hole spin relaxation in Ge/Si nanowire quantum dots
• Self-controlled growth of highly uniform Ge/Si hut wires for scalable qubit devices
• Electric-field dependent g-factor anisotropy in Ge-Si core-shell nanowire quantum dots
• Perturbation theory for an Anderson quantum dot asymmetrically attached to two superconducting leads
• Large thermoelectric power and figure of merit in a ferromagnetic-quantum dot-superconducting device
• Cooper-pair based photon entanglement without isolated emitters
• SiGe quantum dots for fast hole spin Rabi oscillations
• Multiple Andreev reflections and Shapiro steps in a Ge-Si nanowire Josephson junction
• Ballistic supercurrent discretization and micrometer-long Josephson coupling in germanium
• Josephson Current through a Semiconductor Nanowire: effect of strong spin-orbit coupling and Zeeman splitting
• Observation of spin-selective tunneling in SiGe nanocrystals
• Giant g factor tuning of long-lived electron spins in Ge
• Quantum dot attached to superconducting leads: Relation between symmetric and asymmetric coupling
• Transport mirages in single-molecule devices
• Coherent Charge Transport in Ballistic InSb Nanowire Josephson Junctions
• Josephson effect in a few-hole quantum dot
• Practical Guide to Quantum Phase Transitions in Quantum-Dot-Based Tunable Josephson Junctions
• Subgap features due to quasiparticle tunneling in quantum dots coupled to superconducting leads
• A fabrication guide for planar silicon quantum dot heterostructures
• Single-electron charge sensing in self-assembled quantum dots
• Charge-noise induced dephasing in silicon hole-spin qubits
• Entangled Photon Pair Generation in Hybrid Superconductor-Semiconductor Quantum Dot Devices
• Non-equilibrium transport through quantum dots with Dzyaloshinsky--Moriya--Kondo interaction
• Zero field splitting of heavy-hole states in quantum dots
• Stable quantum dots in an InSb two-dimensional electron gas
• Exchange cotunneling through quantum dots with spin-orbit coupling
• Observation of the anisotropic Dirac cone in the band dispersion of 112-structured iron-based superconductor Ca0.9La0.1FeAs2
• Topological quantum phase transition between Fermi liquid phases in an Anderson impurity model
• Hole spin in tunable Ge hut wire double quantum dot
• Entanglement control and magic angles for acceptor qubits in Si
• Interplay of Coulomb interaction and spin-orbit effects in multi-level quantum dots
• Josephson response of a conventional and a noncentrosymmetric superconductor coupled via a double quantum dot
• Hybrid high-temperature superconductor-semiconductor tunnel diode
• Spin pumping through quantum dots
• Quantum dot spectroscopy of proximity-induced superconductivity in a two-dimensional electron gas
• Supercurrent through an Andreev trimer
• Long-range exchange interaction between spin qubits mediated by a superconducting link at finite magnetic field
• Experimental investigation of the optical spin selection rules in bulk Si and Ge/Si quantum dots
• Assessing the potential of Ge/SiGe quantum dots as hosts for singlet-triplet qubits
• Spin qubit manipulation of acceptor bound states in group IV quantum wells
• A Silicon Nanocrystal Tunnel Field Effect Transistor
• Many-body perturbation theory for the superconducting quantum dot: Fundamental role of the magnetic field
• Finite-bias conductance anomalies at a singlet-triplet crossing
• Optical stabilization of voltage fluctuations in half-Josephson lasers
• Controlling superconducting transistor by coherent light