Pauli-Spin-Blockade Transport through a Silicon Double Quantum Dot

TL;DR

This paper reports on resonant tunneling measurements in a silicon double quantum dot, revealing Pauli spin blockade effects and phonon-assisted tunneling, with implications for silicon spin qubits and quantum information.

Contribution

It demonstrates the observation of Pauli spin blockade and phonon-assisted tunneling in silicon double quantum dots, advancing silicon spin qubit research.

Findings

Observation of Pauli spin blockade in silicon quantum dots

Identification of phonon emission as a mechanism for lifting blockade

Potential for silicon-based spin quantum information processing

Abstract

We present measurements of resonant tunneling through discrete energy levels of a silicon double quantum dot formed in a thin silicon-on-insulator layer. In the absence of piezoelectric phonon coupling, spontaneous phonon emission with deformation-potential coupling accounts for inelastic tunneling through the ground states of the two dots. Such transport measurements enable us to observe a Pauli spin blockade due to effective two-electron spin-triplet correlations, evident in a distinct bias-polarity dependence of resonant tunneling through the ground states. The blockade is lifted by the excited-state resonance by virtue of efficient phonon emission between the ground states. Our experiment demonstrates considerable potential for investigating silicon-based spin dynamics and spin-based quantum information processing.