Laughlin's Topological Charge Pump in an Atomic Hall Cylinder

Area of Science:

• Quantum Physics
• Condensed Matter Physics
• Atomic Physics

Background:

• The quantum Hall effect in two-dimensional electron gases was theoretically explained by Laughlin's thought experiment.
• Laughlin's proposal involved a quantum Hall cylinder with a periodically driven axial magnetic field.
• This laid the foundation for understanding topological quantum matter.

Purpose of the Study:

• To experimentally realize Laughlin's quantum Hall effect thought experiment.
• To demonstrate the nontrivial topology of quantum Hall insulators.
• To provide a platform for studying topological quantum matter.

Main Methods:

• Utilized an ultracold gas of dysprosium atoms.
• Encoded the cyclic dimension in the electronic spin of the atoms.
• Controlled the axial magnetic field using phases of laser-induced spin-orbit couplings.

Main Results:

• Successfully realized the milestone experiment proposed by Laughlin.
• Provided a direct experimental manifestation of the nontrivial topology in quantum Hall insulators.
• The system exhibited quantized motion of atoms analogous to electrons.

Conclusions:

• The experiment validates Laughlin's theoretical proposal for the quantum Hall effect.
• This work offers a new experimental approach to topological quantum matter.
• The methodology can be extended to investigate strongly correlated topological systems.