  The harvesting of ambient radio-frequency (RF) energy is an attractive and
clean way to realize the idea of self-powered electronics. Here we present a
design for a microwave energy harvester based on a nanoscale spintronic diode
(NSD). This diode contains a magnetic tunnel junction with a canted
magnetization of the free layer, and can convert RF energy over the frequency
range from 100 MHz to 1.2 GHz into DC electric voltage. An attractive property
of the developed NSD is the generation of an almost constant DC voltage in a
wide range of frequencies of the external RF signals. We further show that the
developed NSD provides sufficient DC voltage to power a low-power nanodevice -
a black phosphorus photo-sensor. Our results demonstrate that the developed NSD
could pave the way for using spintronic detectors as building blocks for
self-powered nano-systems, such as implantable biomedical devices, wireless
sensors, and portable electronics.
