Patterned magnetic recording disk with high bit-aspect-ratio and master mold for nanoimprinting the disk

A magnetic recording disk drive comprising:

• a patterned-media disk comprising a substrate and a plurality of substantially identical discrete magnetizable islands on the substrate representing discrete data bits, the islands being arranged into a plurality of concentric circular tracks with a track pitch greater than or equal to 26 nm and less than or equal to 54 nm and spaced-apart along the tracks with an along-the-track bit pitch greater than or equal to 13 nm and less than or equal to 27 nm, the islands having an areal bit density greater than or equal to 1 Terabits/in2 and a bit aspect ratio (BAR) equal to or greater than 2, where BAR is the ratio of linear island density in bits per inch (BPI) in the along-the-track direction to track density in tracks per inch (TPI) in the cross-track direction;
• a write head for magnetizing the discrete islands;
• a read head for reading the magnetized islands;
• and
• an actuator connected to the write head and read head for moving the write head and read head across the disk to access the islands.