We discovered for the first time that light can twist metal to control the chirality of metal nanostructures (hereafter, chiral metal nanoneedles). The helicity of optical vortices is transferred to the constituent elements of the irradiated material (mostly melted material), resulting in the formation of chiral metal nanoneedles. The chirality of these nanoneedles could be controlled by just changing the sign of the helicity of the optical vortex. The tip curvature of these chiral nanoneedles was measured to be <40 nm, which is less than 1/25th of the laser wavelength (1064 nm). Such chiral metal nanoneedles will enable us to selectively distinguish the chirality and optical activity of molecules and chemical composites on a nanoscale and they will provide chiral selectivity for nanoscale imaging systems (e.g., atomic force microscopes), chemical reactions on plasmonic nanostructures, and planar metamaterials.

BackgroundLymphoid neoplasm with 18q21.3/BCL2 and 8q24/MYC translocation to immunoglobulin (IG) genes as dual-hit lymphoma/leukemia is very rare and known to have a poor clinical outcome. Design and MethodsTo clarify the clinicopathological characteristics of this malignancy, we analyzed 27 cases of cytogenetically proven dual-hit lymphoma/leukemia. ResultsDual-hit lymphoma/leukemia was diagnosed at presentation in 22 cases and at relapse or disease progression in 5 cases. At the time of diagnosis of dual-hit lymphoma/leukemia, extranodal involvement was found in 25 cases (93%) and central nervous system involvement occurred in 15 cases (56%). The median survival and 1-year survival rate of the 27 cases were only 6 months and 22%, respectively, after diagnosis of the dual-hit lymphoma/leukemia. Seven cases of triple-hit lymphoma/leukemia (dual-hit lymphoma/leukemia with 3q27/BCL6 translocation) were included; the median survival of these patients was only 4 months from the diagnosis of the dual-hit lymphoma/leukemia. The duration of survival of the patients with a triple-hit malignancy was shorter than that of the other 20 cases of dual-hit lymphoma/leukemia (p=0.02). The translocation partner of MYC subdivided the dual-hit cases into two groups; 14 cases of IGH and 13 cases of IGK/L. The MIB-1 index was investigated in 14 cases with aggressive B-cell lymphoma, and was higher in the group with MYC-IGH translocation (n=7) than in the MYC-IGK/L group (n=7) (p=0.02). Overall survival was not different between the MYC-IGH translocation group (n=14) and the MYC-IGK or MYC-IGL translocation group (n=13). ConclusionsDual-hit lymphoma/leukemia is a rare but distinct mature B-cell neoplasm with an extremely poor prognosis characterized by frequent extranodal involvement and central nervous system progression with either of the translocation partners of MYC.

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We discovered that chiral nanoneedles fabricated by vortex laser ablation can be used to visualize the helicity of an optical vortex. The orbital angular momentum of light determines the chirality of the nanoneedles, since it is transferred from the optical vortex to the metal. Only the spin angular momentum of the optical vortex can reinforce the helical structure of the created chiral nanoneedles. We also found that optical vortices with the same total angular momentum (defined as the sum of the orbital and spin angular momenta) are degenerate, and they generate nanoneedles with the same chirality and spiral frequency. DOI: 10.1103/PhysRevLett.110.143603 PACS numbers: 42.50.Tx, 42.50.Wk, 79.20.Ds, 79.20.Eb Light that has a helical wave front due to an azimuthal phase shift, expðiL Þ (where L is an integer known as the topological charge), carries orbital angular momentum, L@. Such light is referred as an optical vortex [1][2][3][4]. Optical vortices have been widely investigated for applications such as optical trapping and guiding [5][6][7], as well as superresolution microscopy [8,9]. Circularly polarized light has a helical electric field and a spin angular momentum, S@, associated with its circular polarization. Optical vortices with circular polarization exhibit both wave front and polarization helicities, and a total angular momentum, J@ [10-12], which is defined as the sum of the orbital and spin angular momenta. This angular momentum is evidenced by the orbital and spinning motions of trapped particles in optical tweezers.To date, several researchers have intensely studied the interaction of structured light, such as radially polarized beams, with plasmonic or metallic structures [13][14][15]. However, these previous studies mostly focused on optical properties, such as mode selection, plasmon focusing, etc., of plasmonic or metallic structures, including photonic crystals as well as plasmonic waveguides, prepared by conventional integrated photonic circuit techniques based on lithography and chemical etching. There are few reports on the use of structured light itself to form chiral structures on the nanoscale. Recently, we discovered that the helicity of a circularly polarized optical vortex can be directly transferred to an irradiated metal sample, resulting in the formation of chiral nanoneedles [16][17][18]. This is the first demonstration, to the best of our knowledge, of nanostructures created by structured light with angular momenta, and it clearly represents a new scientific phenomenon.We have also investigated control of the chirality of formed nanoneedles by changing the sign of the optical vortex helicity. Chiral nanostructures have the potential to form many new material structures [19], including planar chiral metamaterials [20,21] and plasmonic nanostructures [22,23]. They can also be used to selectively identify the chirality of chemical composites in nanoscale imaging systems, such as atomic force and scanning tunnel microscopes [24][25][26][27].However, it is currently unclear whe...

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