Disclosed herein is a detection device comprising sensors with spin torque oscillators (STOs), at least one fluidic channel configured to receive molecules to be detected, and detection circuitry coupled to the sensors. At least some of the molecules to be detected are labeled by magnetic nanoparticles (MNPs). The presence of one or more MNPs in the vicinity of a STO subjected to a bias current changes the oscillation frequency of the STO. The sensors are encapsulated by a material, such as an insulator, separating the sensors from the at least one fluidic channel. A surface of the material provides binding sites for the molecules to be detected. The detection circuitry is configured to detect changes in the oscillation frequencies of the sensors in response to presence or absence of one or more MNPs coupled to one or more binding sites associated with the sensors.

According to one embodiment, a magnetic sensor includes a first element, a first wire, and a first magnetic part. The first element includes a first magnetic layer, a first counter magnetic layer, and a first nonmagnetic layer provided between the first magnetic layer and the first counter magnetic layer. A direction from the first counter magnetic layer toward the first magnetic layer is along a first direction. The first wire extends in a second direction crossing the first direction. The first magnetic part includes a first region and a first counter region. At least a portion of the first wire is between the first region and the first counter region in the first direction.

A magnetoresistive memory cell is provided including a substrate. An inter-layer dielectric layer is disposed on the substrate. A via structure is disposed in the inter-layer dielectric layer. A magnetic pinned layer is disposed on the via structure. A tunnel barrier layer is disposed on the magnetic pinned layer to cover a top and a sidewall of the magnetic pinned layer, wherein the tunnel barrier layer comprises a horizontal extending portion outward from a bottom of the sidewall. A magnetic free layer with a -like structure is disposed on the tunnel barrier layer, wherein the magnetic free layer is isolated from the magnetic pinned layer by the tunnel bather layer. A spacer is disposed on the sidewall of the magnetic free layer. The spacer extends to the inter-layer dielectric layer.

A dual magnetic tunnel junction (DMTJ) is disclosed with a PL1/TB1/free layer/TB2/PL2/capping layer configuration wherein a first tunnel barrier (TB1) has a substantially lower resistancearea (RA.sub.1) product than RA.sub.2 for an overlying second tunnel barrier (TB2) to provide an acceptable net magnetoresistive ratio (DRR). Moreover, magnetizations in first and second pinned layers, PL1 and PL2, respectively, are aligned antiparallel to enable a lower critical switching current than when in a parallel alignment. An oxide capping layer having a RA.sub.CAP is formed on PL2 to provide higher PL2 stability. The condition RA.sub.1<RA.sub.2 and RA.sub.CAP<RA.sub.2 is achieved when TB1 and the oxide capping layer have one or both of a smaller thickness and a lower oxidation state than TB2, are comprised of conductive (metal) channels in a metal oxide or metal oxynitride matrix, or are comprised of a doped metal oxide or doped metal oxynitride layer.

An electrical device structure including a magnetic tunnel junction structure having a first tunnel junction dielectric layer positioned between a free magnetization layer and a fixed magnetization layer. A magnetization enhancement stack present on the magnetic tunnel junction structure. The magnetization enhancement stack includes a second tunnel junction layer that is in contact with the free magnetization layer of the magnetic tunnel junction structure, a metal contact layer present on the second tunnel junction layer, and a metal electrode layer present on the metal contact layer. A metallic ring on a sidewall of the magnetic enhancement stack, wherein a base of the metallic ring may be in contact with the free magnetization layer of the magnetic tunnel junction structure.

A multi-state memory and a method for manufacturing the same. A magnetoresistive tunnel junction is disposed on a spin-orbit coupling layer, and thermal annealing is performed after dopant ions are injected from a side of the magnetoresistive tunnel junction. The concentration of dopant ions in the magnetoresistive tunnel junction has a gradient variation along the direction that is perpendicular to the direction of the current and within the plane in which the spin-orbit coupling layer is located. Symmetry along the direction perpendicular to the direction of the current is broken. In a case a current flows into the spin-orbit coupling layer, resistance are outputted in multiple states in linearity with the current. The multi-state storage is achieved. It can meet a requirement on hardware of neural network synapses, and is applicable to calculation in a neural network.

A magnetic memory according to one embodiment of the present invention comprises: a magnetic tunnel junction comprising a free layer, a reference layer, and a tunnel barrier layer disposed between the free layer and the reference layer; a first conductive line disposed adjacent to the free layer; and a second conductive line disposed adjacent to the free layer and intersecting the first conductive line. A magnetization switching method of the magnetic memory comprises the steps of: applying an alternating current-type first current having a first frequency to the first conductive line; and applying an alternating current-type second current having the first frequency to the second conductive line. The free layer performs magnetization reversal, using the first current and the second current, and the magnetic tunnel junction is disposed on an intersection point between the first conductive line and the second conductive line.

A perpendicular spin transfer torque MRAM memory cell includes a magnetic tunnel junction that has a free layer, a pinned layer and a tunnel barrier between the free layer and the pinned layer. The free layer has a switchable direction of magnetization perpendicular to the plane of the free layer. A cap layer is provided adjacent to the magnetic tunnel junction. The thickness of the cap layer is increased so that the cap layer acts as a heating layer, which results in a reduction of the current density during writing and increases the write margin. In some embodiments, a resistive heating layer is added to the memory cell, adjacent to the cap layer, in order to achieve the lower current density and increased write margin while also improving signal to noise ration during reading by eliminating shot noise.

A magnetic tunnel junction (MTJ) is disclosed wherein a nitride diffusion barrier (NDB) has a L2/L1/NL or NL/L1/L2 configuration wherein NL is a metal nitride or metal oxynitride layer, L2 blocks oxygen diffusion from an adjoining Hk enhancing layer, and L1 prevents nitrogen diffusion from NL to the free layer (FL) thereby enhancing magnetoresistive ratio and FL thermal stability, and minimizing resistance x area product for the MTJ. NL is the uppermost layer in a bottom spin valve configuration, or is formed on a seed layer in a top spin valve configuration such that L2 and L1 are always between NL and the FL or pinned layer, respectively. In other embodiments, one or both of L1 and L2 are partially oxidized. Moreover, either L2 or L1 may be omitted when the other of L1 and L2 is partially oxidized. A spacer between the FL and L2 is optional.

A magnetoresistive random access memory (MRAM) including spin-transfer torque (STT) MRAM is provided that has enhanced data retention. The enhanced data retention is provided by constructing a MTJ pillar having a temperature-independent Delta, where Delta is Delta=Eb/kt, wherein Eb is the activation energy, k is the Boltzmann's constant, and T is the absolute temperature. Notably, the present application provides a way for EB to actually increase with temperature, which can cancel the effect of the term kT, resulting in a temperature independent Delta.