Dynamical behavior of damped driven coupled single electron simple harmonic oscillators

TL;DR

This study investigates the dynamical behavior of trapped electrons in a silicon MOSFET using microwave spectroscopy, modeling their interactions as coupled damped harmonic oscillators, with implications for quantum information processing.

Contribution

It demonstrates that trap dynamics can be described by a classical harmonic oscillator model and shows potential for multi-qubit quantum circuits within a single transistor.

Findings

Over 1000 traps can be individually addressed.

Trap interactions modulate the drain current.

The model enables extraction of coherence and coupling parameters.

Abstract

Coherent coupling between a large number of qubits is the goal for scalable approaches to solid state quantum information processing. Prototype systems can be characterized by spectroscopic techniques. Here, we use pulsed-continuous wave microwave spectroscopy to study the behavior of electrons trapped at defects within the gate dielectric of a sol-gel-based high-k silicon MOSFET. Disorder leads to a wide distribution in trap properties, allowing more than 1000 traps to be individually addressed in a single transistor within the accessible frequency domain. Their dynamical behavior is explored by pulsing the microwave excitation over a range of times comparable to the phase coherence time and the lifetime of the electron in the trap. Trap occupancy is limited to a single electron, which can be manipulated by resonant microwave excitation and the resulting change in trap occupancy is detected by the change in the channel current of the transistor. The trap behavior is described by a classical damped driven simple harmonic oscillator model, with the phase coherence, lifetime and coupling strength parameters derived from a continuous wave (CW) measurement only. For pulse times shorter than the phase coherence time, the energy exchange between traps, due to the coupling, strongly modulates the observed drain current change. This effect could be exploited for 2-qubit gate operation. The very large number of resonances observed in this system would allow a complex multi-qubit quantum mechanical circuit to be realized by this mechanism using only a single transistor.