Abstract: A superconductor thermal filter is disclosed that includes a normal metal layer having a first side, an insulating layer overlying the first side of the normal metal layer, and a multilayer superconductor structure having a first side overlying a side of the insulating layer opposite the side that overlies the normal metal layer. The multilayer superconductor structure is comprised of a plurality of superconductor layers with each superconductor layer having a smaller superconducting energy band gap than the preceding superconductor as the superconductor layers extend away from the normal metal layer. The thermal filter further includes a normal metal layer quasiparticle trap having a first side and a second side with the first side being disposed on a second side of the multilayer superconductor. A bias voltage is applied between the normal metal layer and the normal metal layer quasiparticle trap to remove hot electrons from the normal metal layer.

Abstract: A superconductor thermal filter is disclosed that includes a normal metal layer having a first side, an insulating layer overlying the first side of the normal metal layer, and a multilayer superconductor structure having a first side overlying a side of the insulting layer opposite the side that overlies the normal metal layer. The multilayer superconductor structure is comprised of a plurality of superconductor layers with each superconductor layer having a smaller superconducting energy band gap than the preceding superconductor as the superconductor layers extend away from the normal metal layer. The thermal filter further includes a normal metal layer quasiparticle trap having a first side and a second side with the first side being disposed on a second side of the multilayer superconductor. A bias voltage is applied between the normal metal layer and the normal metal layer quasiparticle trap to remove hot electrons from the normal metal layer.

Abstract: A plant protector can include a plurality of vertical members, a first ring member, and a handle assembly. The plurality of vertical members can extend along respective arcuate paths between respective bottom ends and respective top ends. The bottom ends can be spaced about a bottom periphery and the top ends can be spaced about a top periphery. A plurality of the plant protectors are stackable on one another with the top periphery of an upper plant protector receivable in the bottom periphery of a lower plant protector. The first ring member can interconnect the top ends of the plurality of vertical members. The handle assembly can include a second ring member and a handle mounted on the second ring member. The second ring member can be releasibly engageable with the first ring member.