Awschalom Group

Spin Dynamics and Quantum Information Processing in Semiconductors and Molecules

Our group is primarily concerned with understanding electron and nuclear spin dynamics in semiconductors and molecules as well as engineering quantum states for information processing and sensing applications. Our experimental program combines quantum optics with electron-spin resonance, materials engineering, and nanofabrication. We are focused on developing experimental tools and uncovering new systems that could expand the technological impact of quantum coherence in emerging material systems. Certain point defects in semiconductors, such as the nitrogen vacancy center in diamond or the neutral divacancy in silicon carbide, exhibit long-lived spin coherence that persist up to room temperature. The ability to design individual quantum states and their hosts with the power of chemical synthesis offers new opportunities for the field, spanning quantum sensing, communication, and computing. Harnessing these spin states as atomic-scale probes of electromagnetic fields promises to lead to nanoscale nuclear magnetic resonance, new tools for bio-sensing, and a better understanding of semiconductor electronics.

To read more about our studies, explore the links below:

Quantum Information Processing in Diamond

The fundamental quantum-mechanical nature of spin makes it an ideal candidate for use as a quantum bit, the basic unit of information in a quantum computing architecture. Individual spins may be initialized, coherently controlled, and read out using a variety of optical and electronic techniques. In particular, point defects in crystals have many analogous properties to atoms trapped in vacuum, including localized electronic states and sharp optical and spin transitions. In certain defects, electronic spin states are insulated from lattice dynamics, leading to long quantum coherence times that persist even up to room temperature.

Spin Control in Silicon Carbide and Other Materials

We are exploring defects in a variety of wide-bandgap materials, such as the divacancy in silicon carbide (SiC). We investigate these defects for both fundamental and applied studies of quantum information processing as well as for developing hybrid quantum systems and nanoscale sensing.

Image courtesy of Daniel Laorenza, Freedman Group (MIT)

Creating and Controlling Molecular Spin Qubits

In addition to having coherence times of up to 10 μs and a spin-photon interface, optically addressable molecular spin qubits have the potential to be tunable, modular and scalable. We leverage chemical synthesis methods for bottom-up design of these molecular qubits. We have demonstrated optical addressability of the spin-1 ground-state of a chromium (IV) molecular complex, shown enhancement of the coherence of the chromium spin qubit through host matrix engineering, and shown the tunability of the spin properties of this class of molecules through ligand field modification. We continue to explore structure-function relationships of novel molecular qubits with potential applications in quantum sensing, communication, and computing.