A 2x2 quantum dot array with controllable inter-dot tunnel couplings

Abstract

The interaction between electrons in arrays of electrostatically defined quantum dots is naturally described by a Fermi-Hubbard Hamiltonian. Moreover, the high degree of tunability of these systems make them a powerful platform to simulate different regimes of the Hubbard model. However, most quantum dot array implementations have been limited to one-dimensional linear arrays. In this letter, we present a square lattice unit cell of 2$\times$2 quantum dots defined electrostatically in a AlGaAs/GaAs heterostructure using a double-layer gate technique. We probe the properties of the array using nearby quantum dots operated as charge sensors. We show that we can deterministically and dynamically control the charge occupation in each quantum dot in the single- to few-electron regime. Additionally, we achieve simultaneous individual control of the nearest-neighbor tunnel couplings over a range 0-40~$\mu$eV. Finally, we demonstrate fast ($\sim 1$~$\mu$s) single-shot readout of the spin state of electrons in the dots, through spin-to-charge conversion via Pauli spin blockade. These advances pave the way to analog quantum simulations in two dimensions, not previously accessible in quantum dot systems.

arXiv comment5 pages, 3 figures, 1 table

References in corpus (25)

• Quantum Computation with Quantum Dots
• Electron transport through double quantum dots
• Single-shot read-out of an individual electron spin in a quantum dot
• Surprises on the Way from 1D to 2D Quantum Magnets: the Novel Ladder Materials
• A Mott insulator of fermionic atoms in an optical lattice
• Experimental realization of a long-range antiferromagnet in the Hubbard model with ultracold atoms
• Triplet-Singlet Spin Relaxation via Nuclei in a Double Quantum Dot
• Spin and Charge Resolved Quantum Gas Microscopy of Antiferromagnetic Order in Hubbard Chains
• Observation of Spatial Charge and Spin Correlations in the 2D Fermi-Hubbard Model
• Quantum simulation of a Fermi-Hubbard model using a semiconductor quantum dot array
• Site-resolved measurement of the spin-correlation function in the Hubbard model
• Coherent spin manipulation in an exchange-only qubit
• Collective Coulomb Blockade in an Array of Quantum Dots: A Mott-Hubbard Approach
• Differential Charge Sensing and Charge Delocalization in a Tunable Double Quantum Dot
• The origin of switching noise in GaAs/AlGaAs lateral gated devices
• Quantum simulation of Fermi-Hubbard models in semiconductor quantum dot arrays
• Generic Hubbard model description of semiconductor quantum dot spin qubits
• Charge frustration in a triangular triple quantum dot
• Quantum manipulation of two-electron spin states in metastable double quantum dots
• A few-electron quadruple quantum dot in a closed loop
• Spin of a multielectron quantum dot and its interaction with a neighboring electron
• Spin filling of a quantum dot derived from excited-state spectroscopy
• A triangular triple quantum dot with tunable tunnel couplings
• A linear triple quantum dot system in isolated configuration
• Unravelling Quantum Dot Array Simulators via Singlet-Triplet Measurements

Cited by in corpus (42)

• Review of performance metrics of spin qubits in gated semiconducting nanostructures
• Loading a quantum-dot based "Qubyte" register
• Nagaoka ferromagnetism observed in a quantum dot plaquette
• Probing quantum devices with radio-frequency reflectometry
• Coherent spin state transfer via Heisenberg exchange
• Optimized cavity-mediated dispersive two-qubit gates between spin qubits
• Rapid high-fidelity spin state readout in Si/SiGe quantum dots via radio-frequency reflectometry
• Auto-tuning of double dot devices in situ with machine learning
• Site-selective quantum control in an isotopically enriched 28Si/SiGe quadruple quantum dot
• Charge detection in an array of CMOS quantum dots
• Autonomous tuning and charge state detection of gate defined quantum dots
• A two-dimensional array of single-hole quantum dots
• Protocol for a resonantly-driven three-qubit Toffoli gate with silicon spin qubits
• QFlow lite dataset: A machine-learning approach to the charge states in quantum dot experiments
• Coherent multi-spin exchange coupling in a quantum-dot spin chain
• Signatures of discrete time-crystallinity in transport through an open Fermionic chain
• Hybrid superconductor-semiconductor systems for quantum technology
• Ray-based framework for state identification in quantum dot devices
• Stabilization and manipulation of multispin states in quantum-dot time crystals with Heisenberg interactions
• A robust protocol for entropy measurement in mesoscopic circuits
• Majorana Qubit Readout Using Longitudinal Qubit-Resonator Interaction
• Emergence and Dynamical Stability of Charge Time-Crystal in a Current-Carrying Quantum Dot Simulator
• CMOS Quantum Computing: Toward A Quantum Computer System-on-Chip
• Ab Initio Exact Diagonalization Simulation of the Nagaoka Transition in Quantum Dots
• An automated approach for consecutive tuning of quantum dot arrays
• Quantum coherent control of nonlinear thermoelectric transport in a triple-dot Aharonov-Bohm heat engine
• Highly tunable quadruple quantum dot in a narrow bandgap semiconductor InAs nanowire
• Programmable two-qubit gates in capacitively coupled flopping-mode spin qubits
• A Multiscale Simulation Approach for Germanium-Hole-Based Quantum Processor
• Environment-induced decay dynamics of anti-ferromagnetic order in Mott-Hubbard systems
• Gate reflectometry in dense quantum dot arrays
• Correlation induced $d$-wave pairing in quantum dot square lattice
• Highly tunable 2D silicon quantum dot array with coupling beyond nearest neighbors
• Ray-based classification framework for high-dimensional data
• A 2x2 quantum dot array in silicon with fully tuneable pairwise interdot coupling
• Long-lived circulating currents in strongly correlated nanorings
• Protecting coherence from the environment via Stark many-body localization in a Quantum-Dot Simulator
• Fast raster scan multiplexed charge stability measurements toward high-throughput quantum dot array calibration
• Optimal array geometries for kinetic magnetism and Nagaoka polarons
• Exact diagonalization study of double quantum dots in parallel geometry in zero-bandwidth limit
• Modified Quantum Wheatstone Bridge based on current circulation
• Synchronized coherent charge oscillations in coupled double quantum dots