US 12,405,769 B2
Random number generation unit and computing system
Shunsuke Fukami, Sendai (JP); William Andrew Borders, Sendai (JP); Takuya Funatsu, Sendai (JP); Shun Kanai, Sendai (JP); Keisuke Hayakawa, Sendai (JP); and Hideo Ohno, Sendai (JP)
Assigned to TOHOKU UNIVERSITY, Sendai (JP)
Appl. No. 17/609,123
Filed by TOHOKU UNIVERSITY, Sendai (JP)
PCT Filed May 25, 2020, PCT No. PCT/JP2020/020469
§ 371(c)(1), (2) Date Nov. 5, 2021,
PCT Pub. No. WO2021/002115, PCT Pub. Date Jan. 7, 2021.
Claims priority of application No. 2019-124113 (JP), filed on Jul. 3, 2019.
Prior Publication US 2022/0350572 A1, Nov. 3, 2022
Int. Cl. G06F 7/58 (2006.01)
CPC G06F 7/588 (2013.01) 8 Claims
OG exemplary drawing
 
1. A random number generating unit comprising a magnetic tunnel junction element,
the magnetic tunnel junction element having:
a fixed layer including a ferromagnet and having a magnetization direction fixed substantially;
a free layer including a ferromagnet and having a magnetization direction varying with a first time constant; and
a barrier layer configured as an insulator and disposed between the free layer and the fixed layer,
the magnetic tunnel junction element having a shift magnetic field of an absolute value of 20 millitesla or smaller, wherein
the fixed layer has a plurality of ferromagnetic layers and non-magnetic coupling layers laminated one upon another, and ferromagnetic layers adjacent to each other among the respective ferromagnetic layers are coupled in terms of magnetization by the non-magnetic coupling layers in an antiparallel manner, and
the random number generating unit is configured to:
output one of two output signals at random timing, the timing being independent of an input current or an input voltage, and
control a probability of outputting each of the respective output signals based on the input current or the input voltage.