2018 AFOSR MURI
Hybrid-Materials Valley Optoelectronics For Photon Spin Communication
PO: Dr. Harold Weinstock, Quantum Electronic Solids: quantum.solids@us.af.mil 
PI: David A. Muller, Cornell University
MURI Website

The main objective of this MURI team is to create valley optoelectronics, a new class of highspeed, low-power and miniaturized optoelectronic devices that communicate with photon spins rather than with light intensity. This is possible thanks to the unique properties of two dissimilar material systems, namely (i) the valley degree of freedom (DOF) in single-layer semiconductors that couples exclusively to photon helicity, and (ii) the ability to electrically switch magnetic order in magnetoelectric oxides, enabling ultra-fast, low power control of the valley DOF. We will combine these heterogeneous components into hybrid materials and engineer the atomic scale interactions at their interfaces, generating them in an ultrathin membrane geometry where unprecedented strains can be employed for valley optoelectronics applications beyond the current limit. This hybrid structure is enabled by two new capabilities: the production of atomically-thin semiconductor and ultra-thin, crystalline oxide membranes, and the clean transfer technology for arbitrary stacking of these thin films and membranes, both realized at full wafer-scale.

This class of devices could offer significant advantages as compared to conventional optoelectronics devices that communicate through intensity modulation with significant power consumption. They are power-efficient because the operation is based on strong, atomic-scale exchange and spin-orbit fields rather than on weak external electromagnetic fields. They are fast because their operational bandwidth is limited only by fundamental phonon frequencies of the materials. They are compact because they are formed from nanometer-scale films with extremely strong light-matter interactions. These features will open up unprecedented opportunities for optoelectronics, photonics, and quantum optical devices with significant DoD relevance for low voltage, low-power, and ultra-wide bandwidth communication technologies in both the classical and quantum regimes.

To pursue these goals, our MURI team will solve fundamental scientific and engineering challenges: the theoretical design of optimal material platforms for strong interfacial coupling, the synthesis and fabrication of high-quality materials and their heterostructures, the characterization of interfacial electronic and structural coupling (including with sub-picometer precision using a new electron microscope detector), the control of material properties by electrical and mechanical means, and the realization of novel device concepts based on this new hybrid material platform.

The proposed research activities are highly synergistic, and they leverage the interdisciplinary expertise of seven world-leading scientists and engineers from four universities and a collaborator from a DoD laboratory. Our research will make a significant impact on both fundamental science and applied technology in multiple disciplines, including 2D materials and devices; oxide and ferroelectric thin films, integrated optoelectronics and photonics, and quantum information science.