About: Conical surface is a(n) research topic. Over the lifetime, 18666 publication(s) have been published within this topic receiving 125324 citation(s). The topic is also known as: conic surface & generalized cone.
01 Jul 2004-
David R. Yarkony1•Institutions (1)
01 Oct 1996-Reviews of Modern Physics
Abstract: In the Born-Oppenheimer approximation for molecular dynamics as generalized by Born and Huang, nuclei move on multiple potential-energy surfaces corresponding to different electronic states. These surfaces may intersect at a point in the nuclear coordinates with the topology of a double cone. These conical intersections have important consequences for the dynamics. When an adiabatic electronic wave function is transported around a closed loop in nuclear coordinate space that encloses a conical intersection point, it acquires an additional geometric, or Berry, phase. The Schr\"odinger equation for nuclear motion must be modified accordingly. A conical intersection also permits efficient nonadiabatic transitions between potential-energy surfaces. Most examples of the geometric phase in molecular dynamics have been in situations in which a molecular point-group symmetry required the electronic degeneracy and the consequent conical intersection. Similarly, it has been commonly assumed that the conical intersections facilitating nonadiabatic transitions were largely symmetry driven. However, conical intersections also occur in the absence of any symmetry considerations. This review discusses computational tools for finding and characterizing the conical intersections in such systems. Because these purely accidental intersections are difficult to anticipate, they may occur more frequently than previously thought and in unexpected situations, making the geometric phase effect and the occurrence of efficient nonadiabatic transitions more commonplace phenomena. [S0034-6861(96)00404-7]
01 Mar 1979-Journal of Chemical Physics
Abstract: We show how the presence of a conical intersection in the adiabatic potential energy hypersurface can be handled by including a new vector potential in the nuclear‐motion Schrodinger equation. We show how permutational symmetry of the total wave function with respect to interchange of nuclei can be enforced in the Born–Oppenheimer approximation both in the absence and the presence of conical intersections. The treatment of nuclear‐motion wave functions in the presence of conical intersections and the treatment of nuclear‐interchange symmetry in general both require careful consideration of the phases of the electronic and nuclear‐motion wave functions, and this is discussed in detail.
27 Oct 2006-Physical Review Letters
TL;DR: This Letter shows how the dispersion relation of surface plasmon polaritons propagating along a perfectly conducting wire can be tailored by corrugating its surface with a periodic array of radial grooves, opening the way to important applications such as energy concentration on cylindrical wires and superfocusing using conical structures.
Abstract: In this Letter, we show how the dispersion relation of surface plasmon polaritons (SPPs) propagating along a perfectly conducting wire can be tailored by corrugating its surface with a periodic array of radial grooves. In this way, highly localized SPPs can be sustained in the terahertz region of the electromagnetic spectrum. Importantly, the propagation characteristics of these spoof SPPs can be controlled by the surface geometry, opening the way to important applications such as energy concentration on cylindrical wires and superfocusing using conical structures.
22 Jan 1998-
Abstract: The invention provides a prosthetic valve having a generally annular frame with three post and three scallops. The frame is tri-symmetric with an axis of symmetry defined by the axis of blood flow through the valve. The external surface of the frame is generally cylindrical with diameter D. Each leaflet has a truncated spherical surface adjacent to its free edge. The spherical surface is joined tangentially to a truncated conical surface. The half angle of the truncated cone is approximately 37.5°. The radius of the sphere is approximately D/2−0.5 (mm). The leaflet surface is axi-symmetrical with the axis of symmetry being perpendicular to the axis of the valve frame and blood flow.