Provided is a memory device in which the decrease of the effective bandwidth caused by the refresh operation of the memory device has been solved, a memory controller of the memory device, and a memory system thereof. The nanoparticles of the invention comprise a single element or a compound of elements in one or more of groups II, III, IV, V, VI. Corresponding lands on the IC package and substrate are coupled using a solderless compression connector. The apparatus that stores personal information and credit card information uses a level-two authentication password to protect the user’s credit card information.