Reduce thermal conductivity by forming a nano-phononic crystal on a Si slab Xue-Jun Yan, Xiao-Ping Liu, Xu Ni, Ze-Guo Chen, Ming-Hui Lu and Yan-Feng Chen EPL, 106 5 (2014) 56002 Published online: 04 June 2014 DOI: 10.1209/0295-5075/106/56002