Quantum coherent interaction of molecular and defect spins with phonons and magnons

It almost seems inevitable that one day our laptops and supercomputers will reach their maximum capacity. Similarly, radars, detectors, and sensors will become as accurate as possible. One might ask, what would happen next? Is there any new technology that can outperform our existing technologies, all the way from CPUs and memories to the internet and communication? The foundation of current technologies is the transistor, semiconductors, and electricity, which is the motion of electrons in wires. While these technologies have been around for about 70 years, their rate of progress has slowed down because they are reaching their theoretically possible potential. One can expect them to improve slightly in the next few decades, but not with a huge leap as was seen with the first computers.

The next era of technologies will not be dominated by transistors or moving electrons in wires. Instead, it will be based on atom-sized and molecular structures, as well as extreme conditions of matter, such as extremely low temperatures. The laws of physics are different at these extreme scales and temperatures. Objects such as atoms and electrons behave very differently under such conditions. The study of these conditions started in the early 20th century with the advent of quantum mechanics and relativity. However, these extreme conditions were not experimentally accessible until recently. In the past decade or so, the conditions governed by quantum mechanics have been experimentally improved significantly. We are now able to design single molecules and fabricate atom-sized objects. This advancement has led scientists to consider using these capabilities to invent totally new technologies and surpass the limitations of current technology. The dream is to enter a new era of technologies that relies on quantum mechanics and very small, and perhaps cold, objects.

It has been shown both theoretically and to some extent experimentally that quantum-based technologies can outperform our current technologies in a few key aspects. However, the path to quantum technologies is filled with obstacles and unknowns. Research in this field is addressing multiple aspects of these problems, from device fabrication to theoretical formalisms, from performance to noise, and from communication with the devices to storing information. In this manuscript, we focus on some of the challenges that are faced in the advancement of these technologies and attempt to slightly expand the boundaries of science.

We have contributed to the calculation for a newly fabricated device based on a single molecule. This patented device has several advantages over similar devices: it is easier to fabricate and can be controlled electrically. We then theoretically delve deeper into similar devices and make predictions about how the sensitivity of these devices can be enhanced in regions that are only accessible in quantum mechanical regimes. Following this, we look at the magnetic properties of erbium oxide at very low temperatures. We aim to pave the path for the detection of the smallest possible unit of magnetism in this material. If such properties exist, it would be ideal for transferring quantum information from one point to another.