A magnetic random access memory (MRAM) physically unclonable function (PUF) device that uses the geometric variations in magnetic memory cells to generate a random PUF response is described herein. Within the MRAM, one or more magnetic memory cells can be used for the PUF. The PUF response is generated by destabilizing the one or more magnetic memory cells and then allowing them to relax. The MRAM PUF has also a relatively small footprint among all other silicon PUFs. Timing and control signals for the MRAM PUF are also described along with power and delay characteristics for use with field and spin transfer torque driven destabilization operations.

According to one embodiment, a magnetic memory device includes a magnetic portion, a first magnetic layer, a first nonmagnetic layer, a first element portion, first to third interconnects, and a controller. In a first operation, the controller sets the first interconnect to a first potential, the second interconnect to a second potential, and the third interconnect to a third potential. An absolute value of a difference between the second potential and the third potential is greater than that between the first potential and the third potential. In a second operation, the controller sets the first interconnect to a fourth potential, the second interconnect to a fifth potential, and the third interconnect to a sixth potential. An absolute value of a difference between the fifth potential and the sixth potential is less than that between the fourth potential and the sixth potential.

According to one embodiment, a magnetic memory device includes a magnetic portion, a first magnetic layer, a first nonmagnetic layer, a first element portion, first to third interconnects, and a controller. In a first operation, the controller sets the first interconnect to a first potential, the second interconnect to a second potential, and the third interconnect to a third potential. An absolute value of a difference between the second potential and the third potential is greater than that between the first potential and the third potential. In a second operation, the controller sets the first interconnect to a fourth potential, the second interconnect to a fifth potential, and the third interconnect to a sixth potential. An absolute value of a difference between the fifth potential and the sixth potential is less than that between the fourth potential and the sixth potential.

Provided is a magnetic element capable of generating one skyrmion and erasing the one skyrmion. The magnetic element includes a magnet shaped like a substantially rectangular flat plate, an upstream electrode connected to the magnet in a width Wm direction of the magnet and made of a non-magnetic metal, a downstream electrode connected to the magnet in the width Wm direction to oppose the upstream electrode and made of a non-magnetic metal, and a skyrmion sensor configured to detect the skyrmion. Here, a width Wm of the substantially rectangular magnet is such that 3.Math.?>Wm??, where ? denotes a diameter of the skyrmion, a length Hm of the substantially rectangular magnet is such that 2.Math.?>Hm??, and the magnet has a notch structure at the edge between the upstream electrode and the downstream electrode.

A system and method for providing a physically unclonable function (PFU) is described. In operation, the method includes applying a domain wall shift pulse challenge to a plurality of nanowires of a domain wall memory (DWM) array, wherein the nanowires of the domain wall memory (DWM) array have process induced variations, resulting in pinning potentials which affect the velocity of the domain walls along the length of the nanowires. Following the application of the domain wall shift pulse, the response to the challenge is determined by measuring the response of the plurality of nanowires of the domain wall memory to the applied domain wall shift pulse challenge to provide a physically unclonable function (PUF) for the integrated circuit.

To provide a magnetic element capable of performing skyrmion transfer, a skyrmion memory to which this magnetic element is applied, and a shift register, for example, a magnetic element capable of performing skyrmion transfer is provided, the magnetic element providing a transverse transfer arrangement in which the skyrmion is transferred substantially perpendicular to a current between an upstream electrode and a downstream electrode, and including a plurality of stable positions in which the skyrmion exists more stably than in other regions of a magnet, and a skyrmion sensor that detects a position of the skyrmion.

A magnetic storage apparatus is disclosed, and is configured to access data. The magnetic storage apparatus includes a magnetic storage track, a first write apparatus, a second write apparatus, and a drive apparatus. The first write apparatus and the second write apparatus are located at different positions on the magnetic storage track. The first write apparatus is configured to write first data 0 or second data 1. The second write apparatus is configured to write third data 2 and fourth data 3.

Provided is a skyrmion memory circuit capable of circularly transferring a magnetic element skyrmion, comprising one or more current paths in a magnet having a closed-path pattern that are provided surrounding an end region including an end portion of the magnet in a plane of the magnet with the closed-path pattern, and applying current between an outer terminal connected to an outer circumferential portion of the closed-path pattern and an inner circumference electrode connected to an inner circumferential portion of the closed-path pattern, transferring the skyrmion in a direction substantially perpendicular to the direction of the applied current, and circulating the skyrmion in the magnet with the closed-path pattern.

A memory system according to an embodiment includes a plurality of magnetic nanowires, a read unit that reads data from the magnetic nanowires, a shift control unit that shifts domain walls in the magnetic nanowires, and a read control unit. The read control unit is configured to control the read unit to read the data from the magnetic nanowires in parallel, store two or more of the data read in parallel, and when the data corresponding to a first magnetic nanowire of the magnetic nanowires are delayed or advanced as compared to the data corresponding to a second magnetic nanowire of the magnetic nanowires, determines a misalignment in the data and correct the data based on the misalignment.

A magnetic random access memory (MRAM) physically unclonable function (PUF) device that uses the geometric variations in magnetic memory cells to generate a random PUF response is described herein. Within the MRAM, one or more magnetic memory cells can be used for the PUF. The PUF response is generated by destabilizing the one or more magnetic memory cells and then allowing them to relax. The MRAM PUF has also a relatively small foot-print among all other silicon PUFs. Timing and control signals for the MRAM PUF are also described along with power and delay characteristics for use with with field and spin transfer torque driven destabilization operations.