See here: https://www.researchgate.net/profile/Florian_Gross/publicati....
Along those lines:
* CSS Trees: Pointerless b-Trees with a layout optimized for cache lines (http://www.vldb.org/conf/1999/P7.pdf)
* Intel & Oracle's fast architecture-sensitive tree search (combines huge pages, cache line blocking, and SIMD in an optimal layout): http://www.researchgate.net/profile/Jatin_Chhugani/publicati...
* Adaptive radix trees (http://codematch.muehe.org/~leis/papers/ART.pdf)