More current with less particles due to power-law hopping

Area of Science:

• Condensed Matter Physics
• Quantum Transport Phenomena

Background:

• Ordered one-dimensional fermionic systems are crucial for understanding quantum mechanics.
• Power-law hopping describes interactions over extended distances, differing from short-range models.

Purpose of the Study:

• To investigate the universal transport behavior of one-dimensional fermionic systems with power-law hopping.
• To explore the quantum phase diagram and identify novel transport regimes.

Main Methods:

• Analytical calculation of the zero-temperature Drude weight for non-interacting models.
• Investigation of interacting systems to confirm the robustness of the observed phenomena.
• Proposal of persistent current measurements in mesoscopic rings as an experimental signature.

Main Results:

• A novel phase was identified where the zero-temperature Drude weight diverges as the filling fraction approaches zero.
• In this phase, reducing particle numbers counter-intuitively increases transport efficiency.
• This zero-filling transport behavior is robust against number-conserving interactions.

Conclusions:

• The study reveals a unique transport regime in one-dimensional systems with power-law hopping.
• Persistent current measurements in mesoscopic rings can experimentally verify this phase.
• The observed power-law decay of persistent current at high temperatures contrasts with exponential decay in short-range systems.