Fractional Entropy of Multichannel Kondo Systems from Conductance-Charge Relations.

Area of Science:

• Condensed matter physics
• Quantum information science

Background:

• Fractional entropy signifies nonlocal degrees of freedom, including Majorana zero modes and non-Abelian anyons.
• Direct measurement of fractional entropy is experimentally challenging.
• Maxwell relations offer an indirect measurement route via charge measurements.

Purpose of the Study:

• To explore the experimental measurability of fractional entropy in multichannel charge-Kondo systems.
• To connect charge occupation, crucial for entropy calculation, to conductance measurements.
• To investigate the presence and entropy signatures of Majorana and Fibonacci anyons in these systems.

Main Methods:

• Derivation of relations between charge occupation and conductance in multichannel charge-Kondo systems.
• Analysis of recently obtained experimental conductance data.
• Application of Maxwell relations to infer entropy from charge measurements.

Main Results:

• Established a link between charge occupation and conductance, enabling indirect entropy determination.
• Indicated that Majorana and Fibonacci anyon quasiparticles are well-developed in current two- and three-channel charge-Kondo devices.
• Confirmed the experimental measurability of characteristic entropies associated with these anyons, specifically k_{B}logsqrt[2] and k_{B}log[(1+sqrt[5])/2].

Conclusions:

• Fractional entropy, indicative of exotic quasiparticles, is experimentally accessible in multichannel charge-Kondo systems.
• Existing devices demonstrate well-developed Majorana and Fibonacci anyons.
• The study paves the way for experimental verification of topological quantum phenomena through entropy measurements.