Semiconductor quantum dots in silicon demonstrate exceptionally long spin lifetimes as qubits and are therefore promising candidates for quantum information processing. However, control and readout techniques for these devices have thus far employed low frequency electrons, in contrast to high speed temperature readout techniques used in other qubit architectures, and coupling between multiple quantum dot qubits has not been satisfactorily addressed.

This dissertation presents the design and characterization of a semiconductor charge qubit based on double quantum dot in silicon with an integrated microwave resonator for control and readout. The 6 GHz resonator is designed to achieve strong coupling with the quantum dot qubit, allowing the use of circuit QED control and readout techniques which have not previously been applicable to semiconductor qubits. To achieve this coupling, this document demonstrates successful operation of a novel silicon double quantum dot design with a single active metallic layer and a coplanar stripline resonator with a bias tee for dc excitation.

Experiments presented here demonstrate quantum localization and measurement of both electrons on the quantum dot and photons in the resonator. Further, it is shown that the resonator-qubit coupling in these devices is sufficient to reach the strong coupling regime of circuit QED. The details of a measurement setup capable of performing simultaneous low noise measurements of the resonator and quantum dot structure are also presented here.

The ultimate aim of this research is to integrate the long coherence times observed in electron spins in silicon with the sophisticated readout architectures available in circuit QED based quantum information systems. This would allow superconducting qubits to be coupled directly to semiconductor qubits to create hybrid quantum systems with separate quantum memory and processing components.

Essential to all autonomous creatures is the ability to sense the surrounding environment. Evolution has developed complicated sensory structures to help organisms gain knowledge about the physical state of the world. Creatures lacking in advanced sensory systems are more likely at to fall victim to the harsh reality of nature. One of the hallmarks of the advanced lifeforms are highly evolved sensory systems. Sensory receptors are diverse and vary within species and environments. Of the possible sensing modalities, one is of primary use to creatures living in aqueous environments:electrorecption. Their are two classes of creatures that sense electric fields, those that sense passive electric fields and those that actively emit and then detect their own electric field. Some examples of animals with passive electric field sensing abilities include species like skates, sharks, and rays as well as mammals such dolphins and platypuses. Passive electric field sensors are sensitive enough to detect the tiny voltage potentials disturbance from muscle contractions and heart beats. These signal can betray the presence of prey and predators. Creatures with this remarkable sense consequently have an advantage in environments where optical and chemical sensors may fail.

The term active sensory system refers to the need for a creature to emit some form of signal into the environment using its own energy store. One familiar example is the echolocation ability of bats, where the bat emits a ultrasonic pressure wave that reflects off of nearby objects and can be used for hunting small prey. In contrast to passive electrosense which requires the target to generate an electric field, species that use active electrosense generate their own electric fields, normally some order of magnitude larger. Active electrosense has the distinct advantage that the target object need only have a different physical composition from the surrounding fluid. Contrast is generated from the spatial differences in impedance when a target object enters the field. Consequently active electrosense can be used to identify non-living matter. Active electrosense is an example of convergent evolution. Two separate groups of freshwater fish, the Gymnotiformes(South America) and the Mormyridae(Africa) have been shown to actively generate electric fields. We will look to these species for design inspiration.

In this work we will engineer a system to mimic the ability of weakly electric fish to detect, identify and locate objects in the nearby vicinity. In general electrosense has a shorter range than acoustical sensing such as sonar, but applications can be found for navigating in confined spaces and obstacle detection and avoidance. Specifically, we propose and fabricate the design for a complete electrosense system capable of being mounted on an underwater remotely operated vehicle. We then propose ways of processing the sensory data, with the intention of identifying and locating

nearby anomalies.