In the article “A customizable class of colloidal-quantum-dot spasers and plasmonic amplifiers,” the authors have determined that the assignment of the output of their devices to plasmonic lasing, or “spasing”, was incorrect. It is known that such devices can lase in either transverse-electric (TE) or transverse-magnetic (TM) modes, amplifying photons or surface-plasmon polaritons (plasmons), respectively. Based on the cavity design and the measured spacing between cavity modes, the authors concluded in this research article that the lasing modes were plasmonic. More recent polarization-resolved far-field microscopy experiments and calculations have indicated that the above-threshold peaks of the devices shown in this manuscript arose from photonic-mode lasing rather than plasmonic-mode lasing.
As mentioned in the corrected paper published with this erratum, the metallic cavities can support both photonic and plasmonic modes. If the quantum dot stripe is below a certain cutoff thickness, only the plasmonic mode exists. The authors’ first analysis showed that quantum dot stripes with thicknesses of ~100 nm were below this cutoff. Thus, the authors’ fit all of the cavity spectra above to plasmonic modes. However, this analysis was later found to be incorrect. Subsequent work has shown that all of the above devices were likely lasing in photonic (TE) modes. Lasing in a plasmonic mode (i.e., spasing) has been successfully demonstrated if thinner stripes with higher gain values are employed, as in M. Aellen et al., ACS Photonics (2022).
Despite the incorrect assignment of the data in “A customizable class of colloidal-quantum-dot spasers and plasmonic amplifiers” to plasmonic lasing, experiments by the authors in Aellen et al. (2022) have confirmed plasmonic lasing in such devices at cryogenic temperatures. Therefore, the general conclusions from the Science Advances manuscript are still valid. The strategy of combining an open two-dimensional metallic cavity, fabricated by template stripping, with solution deposition of colloidal nanomaterials as a gain medium, provides a customizable, and potentially scalable, approach for creating plasmonic lasers at precise locations on a chip. Moreover, spectrally narrow lasing lines, low excitation thresholds, and high fabrication reproducibility are qualities that are maintained in nanoplatelet plasmonic lasers. However, plasmonic lasing from these devices at room temperature has not yet been realized at the time of this writing.
Please see the HTML version of the paper for the corrections, as the PDF has not been updated.