Quantum phase transition in a resonant level coupled to interacting leads

Area of Science:

• Condensed Matter Physics
• Quantum Mechanics
• Materials Science

Background:

• Luttinger liquids are one-dimensional interacting electronic systems, differing from conventional Fermi liquids.
• Electron tunneling in Luttinger liquids shows unique power-law suppression of current, unlike Fermi liquids.

Purpose of the Study:

• To emulate Luttinger liquid tunneling using a carbon nanotube system.
• To investigate resonant tunneling phenomena in interacting one-dimensional electronic systems.
• To explore quantum phase transitions in controlled experimental setups.

Main Methods:

• Constructed a carbon nanotube system connected to resistive leads to mimic Luttinger liquid tunneling.
• Implemented a double-barrier, resonant-level structure to study resonant tunneling.
• Controlled electron-environment interactions and interaction strength.

Main Results:

• Observed perfect transparency of a resonant level within the interacting environment at low temperatures.
• Found that the resonance width approaches zero, suggesting strong many-body effects.
• Demonstrated a system emulating Luttinger liquid tunneling with tunable parameters.

Conclusions:

• The observed phenomena indicate the presence of a quantum phase transition driven by many-body physics.
• The carbon nanotube system serves as an excellent model for studying quantum critical phenomena.
• Findings have implications for understanding quantum phase transitions in complex systems like cold atoms and correlated materials.