News

STEPFORWARD is a geospatial tool built on Google Maps API to identify minority serving institutions (MSIs), primarily undergraduate institutions (PUIs) and non-R1 institutions within a geographical radius of travel. Higher Education R&D data highlights institutions active in research fields of interest. The tool enables 2DCC researchers and the broader community to identify a diverse range of institutions for outreach visits and research interactions. The 2DCC supports visits to these institutions as part of a travel extension program.

Understanding the superconductivity at the interface of FeSe/SrTiO3 is a problem of contemporary interest in condensed matter physics because of the significant increase in the critical temperature (Tc ~ 50 K) for the onset of superconductivity compared to that of bulk FeSe crystals (Tc ~ 9 K). Additional interest in this problem arises from the possibility of an unconventional pairing mechanism. We used the 2DCC multimodule molecular beam epitaxy (MBE) and surface characterization facility to study the influence of various capping layers on the Tc of ultrathin films of FeSe grown on SrTiO3.

In this project, we use a novel approach for next generation ultra-low-power sensor design by embracing the evolutionary success of animals with extraordinary sensory information processing capabilities that allow them to survive in extreme and resource constrained environments.

Dilute magnetic semiconductors, achieved through substitutional doping of magnetic atoms into semiconducting systems, enable experimental modulation of spin dynamics for novel magneto-electric or magneto-optical devices, especially in 2D transition metal dichalcogenides that accentuate interactions and activate valley degrees of freedom.

The topological Hall effect (THE) is a phenomenon that is a consequence of a Berry phase created by spin textures in real space. Interfacing a topological insulator with a magnetic insulator provides a model platform for studying this phenomenon in a well-controlled manner. This paper reports the first clear evidence for the THE in heterostructures that combine a model topological insulator (Bi2Se3) with a ferromagnetic insulator (BaFe12O19).

Realization of wafer-scale single-crystal films of transition metal dichalcogenides (TMDs) such as WS2 requires epitaxial growth and coalescence of oriented domains to form a continuous monolayer. The domains must be oriented in the same crystallographic direction on the substrate to inhibit the formation of inversion domain boundaries (IDBs), which form when oppositely oriented triangular domains coalesce.

MnBi2Te4 has recently been established as the first intrinsic antiferromagnetic (AFM) topological insulator. Although quantum anomalous Hall effect (QAHE) has been observed in MnBi2Te4, it is only realized with odd numbers of septuple layers due to the AFM interlayer coupling. Therefore, it is crucial to stabilize ferromagnetic (FM) phase in MnBi2Te4. We have discovered a new FM phase with the Curie temperature of 26 K in the MnSb1.8Bi0.2Te4 sample through tuning growth conditions, in contrast to the AFM order seen in the Mn(Bi1-xSbx)2Te4 family.

Double resonance in two-dimensional MoS2 reveals the dynamics of excitons – robust elementary excitations of a 2D crystal – between two sets of low-energy states known as valleys. The accurate assignment of vibrational signatures elucidates the essential physics limiting the performance of a novel class of “valleytronic” devices exploiting the selectivity of valleys to incident light carrying different polarizations.

The Kaindl group at Lawrence Berkeley National Lab recently reported the ultrafast investigation of 1T’-TaTe2, demonstrating a rapid picosecond melting of its trimer cluster lattice superstructure in the low temperature phase.

While previous studies show a large discrepancy of the charge-spin conversion efficiency in topological insulators (TI), the 2DCC research group reports spin-orbit torque switching in a TI-ferrimagnet heterostructure with perpendicular magnetic anisotropy at room temperature.