A new concept for non-volatile memory is demonstrated. This new technique controls the threshold voltage of the chalcogenide storage device by varying the height and duration of the write pulse. Consequently, the chalcogenide device serves as both the access element and the memory element. Therefore, it does not need any access transistor in the memory array. The new memory achieves the requirement of non-volatility, fast writing/reading, random access, high scalability, compact cell size, and low cost.