Tailoring light–matter–spin interactions in colloidal hetero-nanostructures

Abstract

The interplay between light and matter is the basis of many fundamental processes and various applications. Harnessing light-matter interactions in principle allows operation of solid state devices under new physical principles: for example, the a.c. optical Stark effect (OSE) has enabled coherent quantum control schemes of spins in semiconductors, with the potential for realizing quantum devices based on spin qubits. However, as the dimension of semiconductors is reduced, light-matter coupling is typically weakened, thus limiting applications at the nanoscale. Recent experiments have demonstrated significant enhancement of nanoscale light-matter interactions, albeit with the need for a high-finesse cavity, ultimately preventing device down-scaling and integration. Here we report that a sizable OSE can be achieved at substantial energy detuning in a cavity-free colloidal metal-semiconductor core-shell hetero-nanostructure, in which the metal surface plasmon is tuned to resonate spectrally with a semiconductor exciton transition. We further demonstrate that this resonantly enhanced OSE exhibits polarization dependence and provides a viable mechanism for coherent ultrafast spin manipulation within colloidal nanostructures. The plasmon-exciton resonant nature further enables tailoring of both OSE and spin manipulation by tuning plasmon resonance intensity and frequency. These results open a pathway for tailoring light-matter-spin interactions through plasmon-exciton resonant coupling in a judiciously engineered nanostructure, and offer a basis for future applications in quantum information processing at the nanoscale. More generally, integrated nanostructures with resonantly enhanced light-matter interactions should serve as a test bed for other emerging fields, including nano-biophotonics and nano-energy.

Hierarchical synthesis of non-centrosymmetric hybrid nanostructures and enabled plasmon-driven photocatalysis

“…This observation is supported by low-resolution (LR) and high-resolution (HR) transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS) characterization ( Supplementary Figs 1 and 2). It is worthy to note that the monocrystallinity of subunits is critical for the performance of final nc-HNs, particularly when defects become a limitation in the processes such as carrier recombination and transfer 33,34 . In the formation of Au-CdSe heterodimers, the intermedium Ag can be fully converted to the semiconductor CdSe without residue of Ag according to the EDS measurement ( Supplementary Fig.…”

“…Path I shows direct electron-hole pair excitation and dissociation from the semiconductor subunits followed by electron and hole transfer to catalysts and organic hole scavengers in solution, respectively. In this mechanism, the photon absorption of semiconductor subunits is enhanced by the ARTICLE neighbouring plasmonic subunit (that is, near-field electromagnetic enhancement) 34,36,46 . Paths II and III originate from excitation in the plasmonic metal subunits.…”

Rational synthesis and the structure-property relationships of nanoheterostructures: a combinative study of experiments and theory

“…43 Different transition metals, such as Fe, Ni, Cu and Ag, were brought into contact with alumina (modeled by a small cluster, AlO 6 ). This is the first paper that utilized a quantum 15 − were modeled and some modifications were conducted on the separation work.…”

“…Nanoheterostructures (NHSs), defined as the integration of two nanosized segments into one entity, 1-4 have attracted a tremendous amount of attention in current research because of their structural complexities and their potential applications in electronics, 5 optoelectronics, 6 catalysis, 7 etc. The earliest mention of NHSs accompanied the nascent stage of nanoscience, as exemplified by the core-shell noble metal or metal chalcogenide (ME) nanoparticles (NPs), in the 1990s.…”

DNA-programmed self-assembly of photonic nanoarchitectures

“…[1][2][3][4][5][6][7][8] Most studied photonic nanomaterials are noble metal nanoparticles (MNPs) and semiconductor nanocrystals QDs owing to their distinctive photonic characters. When light interacts with a MNP, collective oscillations of conduction electrons with respect to the positive ion background, known as surface plasmons, can be driven by the incident electromagnetic (EM) field.…”