Nagaoka ferromagnetism observed in a quantum dot plaquette

Abstract

Engineered, highly-controllable quantum systems hold promise as simulators of emergent physics beyond the capabilities of classical computers. An important problem in many-body physics is itinerant magnetism, which originates purely from long-range interactions of free electrons and whose existence in real systems has been subject to debate for decades. Here we use a quantum simulator consisting of a four-site square plaquette of quantum dots to demonstrate Nagaoka ferromagnetism. This form of itinerant magnetism has been rigorously studied theoretically but has remained unattainable in experiment. We load the plaquette with three electrons and demonstrate the predicted emergence of spontaneous ferromagnetic correlations through pairwise measurements of spin. We find the ferromagnetic ground state is remarkably robust to engineered disorder in the on-site potentials and can induce a transition to the low-spin state by changing the plaquette topology to an open chain. This demonstration of Nagaoka ferromagnetism highlights that quantum simulators can be used to study physical phenomena that have not yet been observed in any system before. The work also constitutes an important step towards large-scale quantum dot simulators of correlated electron systems.

arXiv commentThis version: main (8 pages, 6 figures) + supplementary (15 pages, 8 figures)

References in corpus (29)

• Quantum Simulation
• Spins in few-electron quantum dots
• Electron transport through double quantum dots
• Coherent control of a single electron spin with electric fields
• Electron spin relaxation by nuclei in semiconductor quantum dots
• Real-time dynamics of lattice gauge theories with a few-qubit quantum computer
• Electron spin decoherence in quantum dots due to interaction with nuclei
• Time-resolved Observation and Control of Superexchange Interactions with Ultracold Atoms in Optical Lattices
• Control and Detection of Singlet-Triplet Mixing in a Random Nuclear Field
• From Nagaoka's ferromagnetism to flat-band ferromagnetism and beyond: An introduction to ferromagnetism in the Hubbard model
• Digital quantum simulation of fermionic models with a superconducting circuit
• Quantum simulation of a Fermi-Hubbard model using a semiconductor quantum dot array
• Two-dimensional Mott-Hubbard electrons in an artificial honeycomb lattice
• Spin Transport in a Mott Insulator of Ultracold Fermions
• Observation of Four-body Ring-exchange Interactions and Anyonic Fractional Statistics
• Enhancement and sign change of magnetic correlations in a driven quantum many-body system
• Quantum Simulation of the Hubbard Model with Dopant Atoms in Silicon
• Experimental realization of plaquette resonating valence bond states with ultracold atoms in optical superlattices
• Quantum simulation of Fermi-Hubbard models in semiconductor quantum dot arrays
• Charge frustration in a triangular triple quantum dot
• Direct observation of incommensurate magnetism in Hubbard chains
• A 2x2 quantum dot array with controllable inter-dot tunnel couplings
• A few-electron quadruple quantum dot in a closed loop
• A triangular triple quantum dot with tunable tunnel couplings
• Nanoscale ferromagnetism in non-magnetic doped semiconductors
• Kondo screening of a high-spin Nagaoka state in a triangular quantum dot
• Probing interaction-induced ferromagnetism in optical superlattices
• Ab Initio Exact Diagonalization Simulation of the Nagaoka Transition in Quantum Dots
• Coherent control of individual electron spins in a two dimensional array of quantum dots

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