Voltage controlled magnetoresistive random access memory (VC MRAM) is a
promising candidate for a future low-power high-density memory. The main causes
of bit errors in VC MRAM are write error and retention error. As the size of
the memory cell decreases, the data retention time decreases, which causes a
transition from the write-error-dominant region to the retention-error-dominant
region at a certain operating time. Here we introduce the characteristic time
of the transition from the write-error-dominant region to the
retention-error-dominant region and analyze how the characteristic time depends
on the effective anisotropy constant, K0β. The characteristic time is
approximately expressed as tcβ=2wΟ, where w is the write
error rate, and Ο is the relaxation time derived by Kalmkov [J. Appl.
Phys. 96, (2004) 1138-1145]. We show that for large K0β, tcβ
increases with increase of K0β similar to Ο. The characteristic time
is a key parameter for designing the VC MRAM for the variety of applications
such as machine learning and artificial intelligence.Comment: 6 pages, 5 figure