Fine and Large Coulomb Diamonds in a Silicon Quantum Dot

TL;DR

This paper investigates the transport properties of silicon quantum dots, revealing two series of Coulomb diamonds with different periodicities, and models the system as double quantum dots in parallel.

Contribution

It provides experimental observation of Coulomb diamonds in silicon quantum dots and introduces a master equation model for double quantum dots in parallel.

Findings

Observation of two series of Coulomb diamonds with different periodicities

Clear source-drain voltage dependence of Coulomb peaks

Experimental results match the double quantum dot model

Abstract

We experimentally study the transport properties of silicon quantum dots (QDs) fabricated from a highly doped n-type silicon-on-insulator wafer. Low noise electrical measurements using a low temperature complementary metal-oxide-semiconductor (LTCMOS) amplifier are performed at 4.2 K in liquid helium. Two series of Coulomb peaks are observed: long-period oscillations and fine structures, and both of them show clear source drain voltage dependence. We also observe two series of Coulomb diamonds having different periodicity. The obtained experimental results are well reproduced by a master equation analysis using a model of double QDs coupled in parallel.