Using Quantum Dots to Simulate Magnetism

Physics 14, s137
Researchers successfully use an array of quantum dots to create and study a Heisenberg spin chain.
C. J. van Diepen et al. [1]

The interaction of electron spins causes many interesting material properties, including magnetism and superconductivity. To better understand these properties, researchers would like to accurately simulate complex spin systems. That, however, is difficult to do on classical computers, as electron spin is a quantum-mechanical phenomenon, so researchers are instead turning to experimental “quantum simulators” to study these systems. Now, Cornelis Jacobus van Diepen and Tzu-Kan Hsiao of Delft University of Technology in the Netherlands and colleagues have experimentally simulated a simple magnetic system using a platform based on quantum dots [1]. While the platform is small enough to numerically simulate on a classical computer, the researchers say their demonstration indicates the viability of quantum dots to probe large-scale spin systems.

The team’s quantum simulator consists of a sandwich of two semiconductors, gallium arsenide and aluminum gallium arsenide. At the interface between the two materials, there are electric potentials that mimic the positive charge of an atomic nucleus. These artificial atomic “nuclei” trap electrons, creating quantum dots.

By tuning the interactions between the electrons in four neighboring quantum dots, the team simulated the behavior of a four-electron “Heisenberg spin chain,” with each quantum dot holding one electron spin. They characterized the system by initializing it in a certain state. Then, they measured the energy of the spins, finding they matched predictions from classical numerical simulations. In addition, they made the spins in the spin chain oscillate in a manner predicted by theory.

In future work, the team says that they plan to simulate spin systems arranged in different lattice configurations. They also hope to investigate using other semiconductors to create their platform, with the aim of making a magnetically quieter environment for the quantum dot spins.

–Sophia Chen

Sophia Chen is a freelance science writer based in Columbus, Ohio.


  1. C. J. van Diepen et al., “Quantum simulation of antiferromagnetic Heisenberg chain with gate-defined quantum dots,” Phys. Rev. X 11, 041025 (2021).

Subject Areas

Quantum InformationQuantum Physics

Related Articles

Controlling Single Photons with Rydberg Superatoms
Atomic and Molecular Physics

Controlling Single Photons with Rydberg Superatoms

New schemes based on Rydberg superatoms placed in optical cavities can be used to manipulate single photons with high efficiency. Read More »

Parametric Amplification for Silicon Quantum Devices
Quantum Information

Parametric Amplification for Silicon Quantum Devices

A new design based on the quantum capacitance of a silicon quantum dot could enable scalable, high-fidelity qubit readout. Read More »

A New Option for Neutral-Atom Quantum Computing
Atomic and Molecular Physics

A New Option for Neutral-Atom Quantum Computing

Two independent teams show that neutral ytterbium-171 atoms can be trapped and used for quantum information processing, bringing quantum computers based on this platform a step closer to reality.    Read More »

More Articles