A nonvolatile ferroelectric memory device has a plurality of ferroelectric memory cells. The ferroelectric memory cells include a first double gate cell for storing a bit of datum, the first double gate cell including a ferroelectric layer and a floating channel layer, wherein a polarity state of the ferroelectric layer affects a resistance of the floating channel layer, the resistance of the floating channel layer corresponding to the bit of datum stored in the first double gate cell; and a second double gate cell selectively turned on by a potential on a selection line to supply a potential of a sense line to the first double gate cell to control read and write operations of the first double gate cell. The present invention also provides methods for operating the nonvolatile ferroelectric memory device.