85 research outputs found
Detection of the interfacial exchange field at a ferromagnetic insulator-nonmagnetic metal interface with pure spin currents
At the interface between a nonmagnetic metal (NM) and a ferromagnetic
insulator (FI) spin current can interact with the magnetization, leading to a
modulation of the spin current. The interfacial exchange field at these FI-NM
interfaces can be probed by placing the interface in contact with the spin
transport channel of a lateral spin valve (LSV) device and observing additional
spin relaxation processes. We study interfacial exchange field in lateral spin
valve devices where Cu spin transport channel is in proximity with
ferromagnetic insulator EuS (EuS-LSV) and yttrium iron garnet
YFeO (YIG-LSV). The spin signals were compared with reference
lateral spin valve devices fabricated on nonmagnetic Si/SiO substrate with
MgO or AlO capping. The nonlocal spin valve signal is about 4 and 6 times
lower in the EuS-LSV and YIG-LSV, respectively. The suppression in the spin
signal has been attributed to enhanced surface spin-flip probability at the
Cu-EuS (or Cu-YIG) interface due to interfacial spin-orbit field. Besides spin
signal suppression we also found widely observed low temperature peak in the
spin signal at 30 K is shifted to higher temperature in the case of
devices in contact with EuS or YIG. Temperature dependence of spin signal for
different injector-detector distances reveal fluctuating exchange field at
these interfaces cause additional spin decoherence which limit spin relaxation
time in addition to conventional sources of spin relaxation. Our results show
that temperature dependent measurement with pure spin current can be used to
probe interfacial exchange field at the ferromagnetic insulator-nonmagnetic
metal interface.Comment: 10 pages, 3 figures, accepted in Physical Review
Recurrent advanced colonic cancer occurring 11 years after initial endoscopic piecemeal resection: a case report
<p>Abstract</p> <p>Background</p> <p>The high frequency of local recurrence occurring after endoscopic piecemeal resection (EPMR) for large colorectal tumors is a serious problem. However, almost all of these cases of local recurrence can be detected within 1 year and cured by additional endoscopic resection. We report a rare case of recurrent advanced colonic cancer diagnosed 11 years after initial EPMR treatment.</p> <p>Case presentation</p> <p>A 65-year-old male was diagnosed with a sigmoid colon lesion following a routine health check-up. Total colonoscopy revealed a 12 mm type 0-Is lesion in the sigmoid colon, which was diagnosed as an adenoma or intramucosal cancer and treated by EPMR in 1996. The post-resection defect was closed completely using metallic endoclips to avoid delayed bleeding. In 2007, at the third follow up, colonoscopy revealed a 20 mm submucosal tumor (SMT) like recurrence at the site of the previous EPMR. The recurrent lesion was treated by laparoscopic assisted sigmoidectomy with lymph node dissection.</p> <p>Conclusion</p> <p>When it is difficult to evaluate the depth and margins of resected tumors following EPMR, it is important that the defect is not closed in order to avoid tumor implantation, missing residual lesions and to enable earlier detection of recurrence. It is crucial that the optimal follow-up protocol for EPMR cases is clarified, particularly how often and for how long they should be followed.</p
Identification and Biosynthesis of Novel Male Specific Esters in the Wings of the Tropical Butterfly, Bicyclus martius sanaos
Superconducting spintronics
The interaction between superconducting and spin-polarized orders has recently emerged as a major research field following a series
of fundamental breakthroughs in charge transport in superconductor-ferromagnet heterodevices which promise new device
functionality. Traditional studies which combine spintronics and superconductivity have mainly focused on the injection of
spin-polarized quasiparticles into superconducting materials. However, a complete synergy between superconducting and magnetic
orders turns out to be possible through the creation of spin-triplet Cooper pairs which are generated at carefully engineered
superconductor interfaces with ferromagnetic materials. Currently, there is intense activity focused on identifying materials
combinations which merge superconductivity and spintronics in order to enhance device functionality and performance. The results
look promising: it has been shown, for example, that superconducting order can greatly enhance central effects in spintronics such as
spin injection and magnetoresistance. Here, we review the experimental and theoretical advances in this field and provide an outlook
for upcoming challenges related to the new concept of superconducting spintronics.J.L. was supported by the Research Council of Norway, Grants No. 205591 and 216700.
J.W.A.R. was supported by the UK Royal Society and the Leverhulme Trust through an
International Network Grant (IN-2013-033).This is the accepted manuscript. The final version is available at http://www.nature.com/nphys/journal/v11/n4/full/nphys3242.html
Quasiparticle-mediated spin Hall effect in a superconductor
In some materials the competition between superconductivity and magnetism brings about a variety of unique phenomena such as the coexistence of superconductivity and magnetism in heavy-fermion superconductors or spin-triplet supercurrent in ferromagnetic Josephson junctions. Recent observations of spin–charge separation in a lateral spin valve with a superconductor evidence that these remarkable properties are applicable to spintronics, although there are still few works exploring this possibility. Here, we report the experimental observation of the quasiparticle-mediated spin Hall effect in a superconductor, NbN. This compound exhibits the inverse spin Hall (ISH) effect even below the superconducting transition temperature. Surprisingly, the ISH signal increases by more than 2,000 times compared with that in the normal state with a decrease of the injected spin current. The effect disappears when the distance between the voltage probes becomes larger than the charge imbalance length, corroborating that the huge ISH signals measured are mediated by quasiparticles.UTokyo Research掲載「超伝導体中で磁気の流れを効率良く電流に変換することに成功」 URI: http://www.u-tokyo.ac.jp/ja/utokyo-research/research-news/efficient-conversion-from-spin-currents-to-charge-currents-in-a-superconductor.htmlUTokyo Research "Efficient conversion from spin currents to charge currents in a superconductor" URI: http://www.u-tokyo.ac.jp/en/utokyo-research/research-news/efficient-conversion-from-spin-currents-to-charge-currents-in-a-superconductor.htm
Quasiparticle-mediated spin Hall effect in a superconductor
In some materials the competition between superconductivity and magnetism brings about a variety of unique phenomena such as the coexistence of superconductivity and magnetism in heavy-fermion superconductors or spin-triplet supercurrent in ferromagnetic Josephson junctions. Recent observations of spin–charge separation in a lateral spin valve with a superconductor evidence that these remarkable properties are applicable to spintronics, although there are still few works exploring this possibility. Here, we report the experimental observation of the quasiparticle-mediated spin Hall effect in a superconductor, NbN. This compound exhibits the inverse spin Hall (ISH) effect even below the superconducting transition temperature. Surprisingly, the ISH signal increases by more than 2,000 times compared with that in the normal state with a decrease of the injected spin current. The effect disappears when the distance between the voltage probes becomes larger than the charge imbalance length, corroborating that the huge ISH signals measured are mediated by quasiparticles.UTokyo Research掲載「超伝導体中で磁気の流れを効率良く電流に変換することに成功」 URI: http://www.u-tokyo.ac.jp/ja/utokyo-research/research-news/efficient-conversion-from-spin-currents-to-charge-currents-in-a-superconductor.htmlUTokyo Research "Efficient conversion from spin currents to charge currents in a superconductor" URI: http://www.u-tokyo.ac.jp/en/utokyo-research/research-news/efficient-conversion-from-spin-currents-to-charge-currents-in-a-superconductor.htm
Mating disruption by a synthetic sex pheromone in the white grub beetle Dasylepida ishigakiensis
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