Improved magnetic information storage using return-point memory

The traditional magnetic storage mechanisms (both analog and digital) apply an external field signal $\mathrm{H(t)}$ to a hysteretic magnetic material, and read the remanent magnetization $\mathrm{M(t)}$ , which is (roughly) proportional to $\mathrm{H(t)}$ . We propose a new analog method of recovering the signal from the magnetic material, making use of the shape of the hysteresis loop $\mathrm{M(H)}$ . The field $H$ , “stored’’ in a region with $N$ domains or particles, can be recovered with fluctuations of order $\text{1/N}$ using the new method—much superior to the $\text{1/}\sqrt{N}$ fluctuations in traditional analog storage.