Collisionally induced transport in periodic potentials.

Area of Science:

• Atomic physics
• Quantum mechanics
• Condensed matter physics

Background:

• Ultracold atoms in optical lattices provide a controllable quantum simulation platform.
• Interparticle collisions significantly influence quantum system dynamics and transport properties.
• Understanding transport in periodic potentials is crucial for quantum technologies.

Purpose of the Study:

• To investigate the transport of ultracold atoms (fermions and bosons) in optical lattices.
• To elucidate the role of interparticle collisions in atomic transport phenomena.
• To explore the induction of transport in fermionic systems via bosonic collisions.

Main Methods:

• Experimental setup involving ultracold atoms in a tight optical lattice.
• Application of an external force to probe transport properties.
• Systematic variation of collisional rates by introducing bosons to a fermionic system.

Main Results:

• Identical fermions exhibit insulating behavior, while bosonic atoms show conducting behavior under an external force.
• Transport can be induced in fermionic systems by creating a collisional regime with added bosons.
• A transition in particle mobility is observed with increasing collisional rate, showing both increasing and decreasing regimes.

Conclusions:

• Interparticle collisions are critical for macroscopic transport in periodic potentials.
• The observed transport behaviors are governed by the distinct collisional properties of fermions and bosons.
• The study provides insights comparable to theoretical models of electron transport in solids (Esaki-Tsu model).