THE EXCITING NEW SCIENCE AT OXIDE INTERFACES
Event details
| Date | 17.05.2013 |
| Hour | 14:15 |
| Speaker | I. Bozovic, Brookhaven National Laboratory, Upton NY 11973, USA |
| Location | |
| Category | Conferences - Seminars |
Oxide Interface Science. The last decade has witnessed explosive growth of research on various oxide hetero-structures, and discoveries of exciting new interface phenomena. We may be witnessing the emergence of Oxide Interface Science, a new field delineated by a distinct new set of problems, techniques, phenomena, and theoretical concepts.
Electronic and/or atomic reconstruction. In hetero-structures. there is always some mismatch between the two constituents - crystallographic (different lattice constants), electrostatic (violation of local charge neutrality) or dynamic (difference in chemical potentials). Consequences are numerous and profound. The atomic structure can be strained and modified; electronic and/or atomic reconstruction may occur, including formation of oxygen and/or cation vacancies as well as large atomic displacements.
Metastability. Most hetero-structures are not thermodynamically stable; the synthesis is at least in part kinetically controlled and the atoms are frozen in one out of many nearly-degenerate metastable states. The actual atomic structure at the interface is thus basically impossible to predict. To determine it experimentally, new tools and techniques for study of buried interfaces are required, and being developed fast.
2D quantum confinement. Digital synthesis of complex oxides – one-unit-cell or even one-atomic-layer at a time - yields ultrathin layers with atomically sharp interfaces. Electrons can be extremely confined in
one direction, while propagating with high mobility in-plane. Ultrathin metals, superconductors, ferromagnets or ferroelectrics host new phenomena, such as massive critical fluctuations, thermal or quantum.
Proximity effects. Interesting new physics occurs also when the two materials exhibit different broken symmetries and order parameters. Competing instabilities, if finely balanced, can result in extreme susceptibility and colossal responses to small perturbations. These may find applications in sensing, ultrafast non-volatile switching, etc., and is hoped to eventually beget new Oxide Electronics.
In this lecture, a number of simple examples will be given, largely drawn from my own practice with atomic-layer-by-layer molecular beam epitaxy (ALL-MBE) of high-Tc cuprate superconductors, but intended to illustrate the more general concepts listed above.
References:
Torchinsky et al., Nature Mater. 12, 387 (2013)
FULL TEXT
Dean et al., Nature Mater.12, 47 (2013)
FULL TEXT
Shi et al., Nature Mater. 11, 850 (2012)
FULL TEXT
Bollinger et al., Nature 472, 458 (2011)
FULL TEXT
Bilbro et al., Nature Phys. 7, 298 (2011)
FULL TEXT
Morenzoni et al., Nature Comm. 2, 272 (2011)
FULL TEXT
Sochnikov et al., Nature Nanotech. 5, 516 (2010)
FULL TEXT
Logvenov et al., Science 326, 699 (2009)
FULL TEXT
Gozar et al., Nature 455, 782 (2008)
FULL TEXT
Gedik et al., Science 316, 425 (2007)
FULL TEXT
Bozovic et al., Nature 422, 873 (2003)
FULL TEXT
Abbamonte et al., Science 297, 581 (2002)
FULL TEXT
Electronic and/or atomic reconstruction. In hetero-structures. there is always some mismatch between the two constituents - crystallographic (different lattice constants), electrostatic (violation of local charge neutrality) or dynamic (difference in chemical potentials). Consequences are numerous and profound. The atomic structure can be strained and modified; electronic and/or atomic reconstruction may occur, including formation of oxygen and/or cation vacancies as well as large atomic displacements.
Metastability. Most hetero-structures are not thermodynamically stable; the synthesis is at least in part kinetically controlled and the atoms are frozen in one out of many nearly-degenerate metastable states. The actual atomic structure at the interface is thus basically impossible to predict. To determine it experimentally, new tools and techniques for study of buried interfaces are required, and being developed fast.
2D quantum confinement. Digital synthesis of complex oxides – one-unit-cell or even one-atomic-layer at a time - yields ultrathin layers with atomically sharp interfaces. Electrons can be extremely confined in
one direction, while propagating with high mobility in-plane. Ultrathin metals, superconductors, ferromagnets or ferroelectrics host new phenomena, such as massive critical fluctuations, thermal or quantum.
Proximity effects. Interesting new physics occurs also when the two materials exhibit different broken symmetries and order parameters. Competing instabilities, if finely balanced, can result in extreme susceptibility and colossal responses to small perturbations. These may find applications in sensing, ultrafast non-volatile switching, etc., and is hoped to eventually beget new Oxide Electronics.
In this lecture, a number of simple examples will be given, largely drawn from my own practice with atomic-layer-by-layer molecular beam epitaxy (ALL-MBE) of high-Tc cuprate superconductors, but intended to illustrate the more general concepts listed above.
References:
Torchinsky et al., Nature Mater. 12, 387 (2013)
FULL TEXT
Dean et al., Nature Mater.12, 47 (2013)
FULL TEXT
Shi et al., Nature Mater. 11, 850 (2012)
FULL TEXT
Bollinger et al., Nature 472, 458 (2011)
FULL TEXT
Bilbro et al., Nature Phys. 7, 298 (2011)
FULL TEXT
Morenzoni et al., Nature Comm. 2, 272 (2011)
FULL TEXT
Sochnikov et al., Nature Nanotech. 5, 516 (2010)
FULL TEXT
Logvenov et al., Science 326, 699 (2009)
FULL TEXT
Gozar et al., Nature 455, 782 (2008)
FULL TEXT
Gedik et al., Science 316, 425 (2007)
FULL TEXT
Bozovic et al., Nature 422, 873 (2003)
FULL TEXT
Abbamonte et al., Science 297, 581 (2002)
FULL TEXT
Practical information
- Informed public
- Free
Organizer
- ICMP (Arnaud Magrez, Raphaël Butté and Woflgang Harbich)
Contact
- D. Pavuna