Search

We analyzed the influence of temperature on the main characteristics of a passive spin-torque microwave detector (STMD): volt-watt sensitivity, signal-to-noise ratio, and minimum detectable microwave power. We reveal that these parameters do not always improve with the decrease of temperature. The developed formalism can be used for the optimization of the practical parameters of a STMD in a wide range of temperatures., Submitted to IEEE Transactions on Magnetics, Vol. 48, No. 11, November 2012

It is known that the spin-transfer torque (STT) effect provides a new method of manipulation of magnetization in nano-scale objects. According to the STT effect bias DC current traversing magnetic multilayers can transfer angular magnetic moments from one layer to another, which can give rise to the micro-wave dynamics of magnetization in the layer. However, it is clear that an inverse effect is also possible. This inverse effect leads to the so-called spin-torque diode effect, first originally observed experimentally in 2005. The spin torque diode effect is a rectification effect of the input microwave current in a magnetoresistive junction. In this case, the resonance oscillations of the junction resistance can mix with the oscillations of the input microwave current and produce a large enough output DC voltage across the junction. The devices, which utilize this effect, are called the spin-torque microwave detectors (STMD). In this chapter we review the general properties of STMDs and consider the performance of a STMD in two dif-ferent dynamic regimes of detector operation: in the well-known traditional in-plane regime of STMD operation and in the recently discovered novel out-of-plane regime of STMD operation. We analyze the performance of a STMD and consider the typical applications for such detectors in both regimes.