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IBM Claims Spintronics Memory Breakthrough
CWmike writes with this excerpt from ComputerWorld: "In a paper set to be published this week in the scientific journal Nature, IBM researchers are claiming a huge breakthrough in spintronics, a technology that could significantly boost capacity and lower power use of memory and storage devices. Spintronics, short for 'spin transport electronics,' uses the natural spin of electrons within a magnetic field in combination with a read/write head to lay down and read back bits of data on semiconductor material. By changing an electron's axis in an up or down orientation — all relative to the space in which it exists — physicists are able to have it represent bits of data. For example, an electron on an upward axis is a one; and an electron on a downward axis is a zero. Spintronics has long faced an intrinsic problem because electrons have only held an 'up or down' orientation for 100 picoseconds. A picosecond is one trillionth of a second [one thousandth of a nanosecond.] One hundred picoseconds is not enough time for a compute cycle, so transistors cannot complete a compute function and data storage is not persistent. In the study published in Nature, IBM Research and the Solid State Physics Laboratory at ETH Zurich announced they had found a way to synchronize electrons, which could extend their spin lifetime by 30 times to 1.1 nanoseconds, the time it takes for a 1 GHz processor to cycle."
Sure, not everyone one who comes to /. is a long time geek. We all start somewhere.
Give me some science on it and tell me some more details.
Since they didn't give a link to it, here's the citation for the paper in question: M. P. Walser, et al., "Direct mapping of the formation of a persistent spin helix", Nature Phys., 2012 (accepted, in press). You can read all of the wonderfully gritty, and hard-to-parse, details in that paper.
If you want to learn more about the science behind spintronics, feel free to peruse:
M. Johnson and R. H. Silsbee, "Interfacial charge-spin coupling: Injection and detection of spin magnetization in metals", Phys. Rev. Lett. 55: 1790-1793, 1985
M. N. Baibich, et al., "Giant magnetoresistance of (001)Fe/(001)Cr magnetic superlattices", Phys. Rev. Lett. 61: 2472-2475, 1988
G. Binasch, et al., "Enhanced magnetoresistance in layered magnetic structures with antiferromagnetic interlayer exchange", Phys. Rev. B 29: 4828, 1989
S. Datta and B. Das, "Electronic analog of the electrooptic modulator", Appl. Phys. Lett. 56: 665-667, 1990
J. Kikkawa and D. Awschalom, "Resonant spin amplification in n-type GaAs", Phys. Rev. Lett. 80: 4313, 1998
B. T. Jonker, et al., "Robust electrical spin injection into a semiconductor heterostructure", Phys. Rev. B 62: 8180-8183, 2000
A. T. Hanbicki, et al., "Efficient electrical spin injection from a magnetic metal/tunnel barrier contact into a semiconductor", Appl. Phys. Lett. 80: 1240, 2002
S. van Dijken, et al., "Room temperature operation of a high output current magnetic tunnel transistor", Appl. Phys. Lett. 80: 3364-3366, 2002
X. Jiang, et al., "Optical detection of hot-electron spin injection into GaAs from a magnetic tunnel transistor source", Phys. Rev. Lett. 90: 256603, 2003
J. Schliemann, et al., "Nonballistic spin-field-effect transistor", Phys. Rev. Lett. 90: 146801, 2003
B. A. Bernevig, et al., "Exact SU(2) symmetry and persistent spin helix in a spin-orbit coupled system", Phys. Rev. Lett. 97: 236601: 2006
X. Lou, et al., "Electrical detection of spin transport in lateral ferromagnet–semiconductor devices", Nature Phys. 3: 197-202, 2007
M. Holub, et al., "Electrical spin injection and threshold reduction in a semiconductor laser", Phys. Rev. Lett. 98: 146603, 2007
I. Appelbaum, et al., "Electronic measurement and control of spin transport in silicon", Nature 447: 295-298, 2007
M. Duckheim and D. Loss, "Resonant spin polarization and spin current in a two-dimensional electron gas", Phys. Rev. B 75: 201305, 2007
B. Behin-Aein, et al., "Proposal for an all-spin logic device with built-in memory", Nature Nano. 5: 266-270, 2010
J. Wunderlich, et al., "Spin Hall effect transistor", Science 330: 1801-1804, 2010
How about a blurb about spintronics already being used in modern hard drive read heads?
I can do better than a blurb, I can provide you with references to the underlying science:
M. Julliere, "Tunneling between ferromagnetic films", Phys. Lett. 54: 225-226, 1975
J. S. Moodera, et al. "Large magnetoresistance at room temperature in ferromagnetic thin film tunnel junctions", Phys. Rev. Lett. 74: 3273-3276
W. H. Butler, et al., "Spin-dependent tunneling conductance of Fe/MgO/Fe sandwiches", Phys. Rev. B. 63: 054416, 2001
J. Mathon and A. Umerski, "Theory of tunneling magnetoresistance of an epitaxial Fe/MgO/Fe (001) junction", Phys. Rev. B. 63: 220403, 2001
M. Bowen, et al., "Large magnetoresistance in Fe/MgO/FeCo(001) epitaxial tunnel junctions on GaAs(001)", Appl. Phys. Lett. 79: 1655, 2001
S. Yuasa, et al., "Giant room-temperature magnetoresistance in single-crystal Fe/MgO/Fe magnetic tunnel junctions", Nature Mater. 3: 868-871, 2004
S. S. P. Parkin, et al., "Giant tunnelling magnetoresistance at room temperature with MgO (100) tunnel barriers" Nature Mater. 3: 862-867, 2004
S. Ikeda, et al., "Tunnel magnetoresistance of 604% at 300 K by suppression of Ta diffusion in CoFeB/MgO/CoFeB pseudo-spin-valves annealed at high temperature", Appl. Phys. Lett. 93: 082508, 2008
1 hectoslashdotter cannot be wrong!
Absence of proof != proof of absence.