2010
Intrinsic Gap and Exciton Condensation in the ƒËT=1 Bilayer System
P. Giudici, K. Muraki, N. Kumada, and T. Fujisawa
Phys. Rev. Lett. 104, 056802 (2010). [abstract]
Wide-Band Capacitance Measurement on a Semiconductor Double Quantum Dot for Studying Tunneling Dynamics
T. Ota, T. Hayashi, K. Muraki, and T. Fujisawa
Appl. Phys. Lett. 96, 032104 (2010). [abstract]
Voltage-controlled group velocity of edge magnetoplasmon in the quantum Hall regime
H. Kamata, T. Ota, K. Muraki, and T. Fujisawa
Phys. Rev. B 81, 085329 (2010). [abstract]
2009
Spin effects in the phase transition of the ƒËT = 1 bilayer electron system
K. Muraki, P. Giudici, and N. Kumada
Int. J. Mod. Phys. B 23, 2587 (2009).
The interplay between one-dimensional confinement and two-dimensional crystallographic anisotropy effects in ballistic hole quantum wires
O. Klochan, A. P. Micolich, L. H. Ho, A. R. Hamilton, K. Muraki, and Y. Hirayama
New J. Phys. 11, 043018 (2009). [abstract]
Electrons and Holes in a 40 nm Thick Silicon Slab at Cryogenic Temperatures
K. Takashina, K. Nishiguchi, Y. Ono, A. Fujiwara, T. Fujisawa, Y. Hirayama, and K. Muraki
Appl. Phys. Lett. 94, 142104 (2009). [abstract]
Room-Temperature Stability of Pt Nanogaps Formed by Self-Breaking
F. Prins, T. Hayashi, B. J. A. de Vos van Steenwijk, B. Gao, E. A. Osorio, K. Muraki, and H. S. J. van der Zant
Appl. Phys. Lett. 94, 123108 (2009). [abstract]
Electron-Spin/Nuclear-Spin Interactions and NMR in Semiconductors
Y. Hirayama, G. Yusa, K. Hashimoto, N. Kumada, T. Ota, and K. Muraki
Semicond. Sci. Technol .24, 023001 (2009). [abstract]
Bidirectional Current Drag Induced by Two-Electron Cotunneling in Coupled Double Quantum Dots
G. Shinkai, T. Hayashi, T. Ota, K. Muraki, and T. Fujisawa
Appl. Phys. Exp. 2, 081101 (2009). [abstract]
2008
Spin-Dependent Phase Diagram of the nu_T=1 Bilayer Electron System
P. Giudici, K. Muraki, N. Kumada, Y. Hirayama, and T. Fujisawa
Phys. Rev. Lett. 100, 106803 (2008). [abstract]
Highly Reproducible Fabrication of Back-Gated GaAs/AlGaAs Heterostructures using AuGeNi Ohmic Contacts with Initial Ni Layer
A. Valeille, K. Muraki, and Y. Hirayama
Appl. Phys. Lett. 92, 152106 (2008). [abstract]
Modulation of Bilayer Quantum Hall States by Tilted-Field-Induced Subband-Landau-Level Coupling
N. Kumada, K. Iwata, K. Tagashira, Y. Shimoda, K. Muraki, Y. Hirayama, and A. Sawada
Phys. Rev. 77, 155324 (2008). [abstract]
Exciton Condensate at a Total Filling Factor of One in Corbino Two-Dimensional Electron Bilayers
L. Tiemann, J. G. S. Lok, W. Dietsche, K. von Klitzing, K. Muraki, D. Schuh, and W. Wegscheider
Phys. Rev. B 77, 033306 (2008). [abstract]
Impact of Long- and short-range disorder on the metallic behaviour of two-dimensional system
W. R. Clarke, C. E. Yasin, A. R. Hamilton, A. P. Micolich, M. Y. Simmons, K. Muraki, Y. Hirayama, M. Pepper, and D. A. Ritchie
Nature Physics 4, 55 (2008). [abstract]
The 0.7 Anomaly in One-Dimensional Hole Quantum Wires
A. R. Hamilton, R. Danneau, O. Klochan, W. R. Clarke, A. P. Micolich, L. H. Ho, M. Y. Simmons, D. A. Ritchie, M. Pepper, K. Muraki, and Y. Hirayama
J. Phys.: Condens. Matter. 20, 164205 (2008). [abstract]
NMR Study of a Canted Antiferromagnet in a Bilayer Quantum Hall System
N. Kumada, K. Muraki , and Y. Hirayama
Physica E 40, 937 (2008). [abstract]
Investigating the Transport Properties of the Excitonic State in Quasi-Corbino Electron Bilayers
L. Tiemann, J. G. S. Lok, W. Dietsche, K. von Klitzing, K. Muraki, D. Schuh, and W. Wegscheider
Physica E 40, 1034 (2008). [abstract]
Metallic Behavior in Low-Disorder Two-Dimensional Hole Systems in the Presence of Long- and Short-Range Disorder
W. R. Clarke, C. E. Yasin, A. R. Hamilton, A. P. Micolich, M. Y. Simmons, K. Muraki, Y. Hirayama, M. Pepper, and D. A. Ritchie
Physica E 40, 1599 (2008). [abstract]
Quantum Transport in One-Dimensional GaAs Hole Systems
A. R. Hamilton, O. Klochan, R. Danneau, W. R. Clarke, L. H. Ho, A. P. Micolich, M. Y. Simmons, M. Pepper, D. A. Ritchie, K. Muraki, and Y. Hirayama
Int. J. Nanotechnology 5, 318 (2008). [abstract]
Nuclear Spin Manipulation in Semiconductor Nanostructures
K. Muraki, G. Yusa, and Y. Hirayama
SPIE Proceedings Vol. 6800, Device and Process Technologies for Microelectronics, MEMS, Photonics, and Nanotechnology IV [abstract]
2007
NMR Evidence for Spin Canting in a Bilayer nu = 2 Quantum Hall System
N. Kumada, K. Muraki , and Y. Hirayama
Phys. Rev. Lett. 99, 076805 (2007). [abstract]
Interaction of Electron and Nuclear Spins in Quantum Wells
K. Muraki, N. Kumada, and Y. Hirayama
Int. J. Mod. Phys. B 21, 1266 (2007).
2006
Low-frequency spin dynamics in a canted antiferromagnet
N. Kumada, K. Muraki, and Y. Hirayama
Science 313, 329 (2006). [abstract]
Electronic transport characteristics in a one-dimensional constriction defined by a triple-gate structure
H.-M. Lee, K. Muraki, E.-Y. Chang, and Y. Hirayama
J. Appl. Phys. 100, 043701 (2006).
Ballistic transport in induced one-dimensional hole systems
O. Klochan, W. R. Clarke, R. Danneau, A. P. Micolich, L. H. Ho, A. R. Hamilton, K. Muraki, and Y. Hirayama
Appl. Phys. Lett. 89, 092105 (2006).
Fabrication of induced two-dimensional hole systems on (311)A GaAs
W. R. Clarke, A. P. Micolich, A. R. Hamilton, M. Y. Simmons, K. Muraki, and Y. Hirayama
J. Appl. Phys. 99, 0237071 (2006).
Nuclear-spin-lattice relaxation in a nu=1 bilayer quantum Hall system
N. Kumada, K. Muraki, and Y. Hirayama
Physica E 34, 164 (2006).
Nanometre-scale nuclear-spin device for quantum information processing
Y. Hirayama, A. Miranowicz, T. Ota, G. Yusa, K. Muraki, S. K. Ozdemir, N. Imoto
J. Phys. Condens. Mat 18, S885 (2006).
2005
Controlled multiple quantum coherences of nuclear spins in a nonometre-scale device
G. Yusa, K. Muraki, K. Takashina, K. Hashimoto, and Y. Hirayama
Nature 434, 1001 (2005). [abstract]
Spin degree of freedom in the nu = 1 bilayer electron system investigated by nuclear spin relaxation
N. Kumada, K. Muraki, K. Hashimoto, and Y. Hirayama
Phys. Rev. Lett 94, 096802 (2005). [abstract]
Effects of inversion asymmetry on electron-nuclear spin coupling in semiconductor heterostructures:
Possible role of spin-orbit interactions
K. Hashimoto, K. Muraki, N. Kumada, T. Saku, and Y. Hirayama
Phys. Rev. Lett 94, 146601 (2005). [abstract]
Resistance oscillations by electron-nuclear spin coupling in microscopic quantum Hall devices
G. Yusa, K. Hashimoto, K. Muraki,T. Saku, and Y. Hirayama
Jpn. J. Appl. Phys. 44, 2669 (2005).
Fabrication and characterization of a 2D hole system in a novel (311)A GaAs SISFET
W. R. Clarke, A. P. Micolich, A. R. Hamilton, M. Y. Simmons, K. Muraki, and Y. Hirayama
Mocroelectron. Journal 36, 327 (2005).
2004
Coulomb drag as a probe of the nature of compressible states in a magnetic field
K. Muraki, J. G. S. Lok, S. Kraus, W. Dietsche, K. von Klitzing, D. Schuh, M. Bichler, and W. Wegscheider
Phys. Rev. Lett. 92, 246801 (2004). [abstract]
Phase diagrams of ƒË = 2 and ƒË = 2/3 quantum Hall states in bilayer systems
N. Kumada, D. Terasawa, M. Morino, K. Tagashira, A. Sawada, Z. F. Ezawa, K. Muraki, Y. Hirayama, and T. Saku
Phys. Rev. B 69, 155319 (2004).
Self-sustaining resistance oscillations: Electron-nuclear spin coupling in mesoscopic quantum Hall devices
G. Yusa, K. Hashimoto, K. Muraki, T. Saku, and Y. Hirayama
Phys. Rev. B 69, 161302(R) (2004).
Intralayer backscattering in narrow GaAs/AlGaAs/GaAs bilayer channels
G. Yusa, K. Muraki, T. Saku, and Y. Hirayama
Phys. Rev. B 69, 085323 (2004).
Molecular phases in coupled quantum dots
M. Rontani, S. Amaha, K. Muraki, F. Manghi, E. Molinari, S. Tarucha, and D. G. Austing
Phys. Rev. B 69, 085327 (2004).
Effects of in-plane magnetic fields on spin transitions in bilayer quantum Hall states
N. Kumada, K. Tagashira, K. Iwata, A. Sawada, Z. F. Ezawa, K. Muraki, T. Saku, and Y. Hirayama
Physica E 22, 36 (2004).
Simultaneous excitation of spins and pseudospins in the bilayer ƒË = 1 quantum Hall state
D. Terasawa, M. Morino, K. Nakada, S. Kozumi, A. Sawada, Z. F. Ezawa, N. Kumada, K. Muraki, T. Saku, and Y. Hirayama
Physica E 22, 52 (2004).
2003
Charge excitation and transport in pseudospin quantum Hall ferromagnets
K. Muraki, T. Saku, and Y. Hirayama
Physica E 18, 107 (2003).
Pulsed-mode operation of nuclear spin polarization in integer quantum Hall systems
T. Machida, T. Yamazaki, K. Ikushima, S. Komiyama, K. Muraki, and Y. Hirayama
Physica E 18, 128 (2003).
Quantum Hall effects at Landau level crossings
Y. Hirayama, K. Muraki, K. Hashimoto, K. Takashina, and T. Saku
Physica E 20, 133 (2003).
Density functional theory application to double quantum dots: Influence of mismatch on the addition energy spectra of vertical diatomic artificial molecules
D. G. Austing, S. Sasaki, K. Muraki, K. Ono, S. Tarucha, M. Barranco, A. Emperador, M. Pi, and F. Garcias
Int. J. Quant. Chem. 91, 498 (2003).
Vertical diatomic artificial molecule in the intermediate-coupling regime in a parallel and perpendicular magnetic field
F. Ancilotto, D. G. Austing, M. Barranco, R. Mayol, K. Muraki, M. Pi, S. Sasaki, and S. Tarucha
Phys. Rev. B 67, 205311 (2003).
2002
Electrically Controlled Nuclear Spin Polarization and Relaxation by Quantum Hall States
K. Hashimoto, K. Muraki, T. Saku, and Y. Hirayama
Phys. Rev. Lett. 88, 176601 (2002). [abstract]
Phase Diagram of Interacting Composite Fermions in the Bilayer nu = 2/3 Quantum Hall Effect
N. Kumada, D. Terasawa, Y. Shimoda, H. Azuhata, A. Sawada, Z. F. Ezawa, K. Muraki, T. Saku, and Y. Hirayama
Phys. Rev. Lett. 89, 116802 (2002). [abstract]
Activation Studies of Pseudospin Quantum Hall Ferromagnets in Double Quantum Wells
K. Muraki, T. Saku, and Y. Hirayama
Physica E 12, 8 (2002)
Spin Polarization of Fractional Quantum Hall Edge Channels Studied by Dynamic Nuclear Polarization
T. Machida, S. Ishizuka, T. Yamazaki, S. Komiyama, K. Muraki, and Y. Hirayama
Phys. Rev. B 65, 233304 (2002). [abstract]
Various Phase Transitions in nu = 2/3 Bilayer Quantum Hall States
N. Kumada, D. Terasawa, Y. Shimoda, H. Azuhata, A. Sawada, Z. F. Ezawa, K. Muraki, T. Saku and Y. Hirayama
Physica E 12, 32 (2002).
Spin Polarization in Fractional Quantum Hall Edge Channels
T. Machida, S. Ishizuka and K. Muraki
Physica E 12, 76 (2002).
Dynamic nuclear-spin polarization induced by scattering between fractional quantum Hall edge channels
T. Machida, T. Yamazaki, S. Komiyama, K. Muraki, and Y. Hirayama
Microelectronic Eng. 63, 63 (2002).
Influence of Mismatch on the Addition Energy Spectra of Vertical Diatomic Artificial Molecules
D. G. Austing, S. Sasaki, K. Muraki, K. Ono, S. Tarucha, M. Barranco, A. Emperador, M. Pi and F. Garcias
Physica E 12, 896 (2002).
2001
Charge Excitations in Easy-Axis and Easy-Plane Quantum Hall Ferromagnets
K. Muraki, T. Saku, and Y. Hirayama
Phys. Rev. Lett. 87, 196801 (2001). [abstract]
Dissociation of Vertical Semiconductor Diatomic Artificial Molecules
M. Pi, A. Emperador, M. Barranco, F. Garcias, K. Muraki, S. Tarucha, and D. G. Austing
Phys. Rev. Lett. 87, 066801 (2001).
Resistance Fluctuations in Quantum Hall Transitions: Network of Compressible-Incompressible Regions
T. Machida, S. Ishizuka, S. Komiyama, K. Muraki, and Y. Hirayama
Phys. Rev. B 63, 045318 (2001).
Magnetic Field Induced Transitions in the Few-Electron Ground States of Artificial Molecules
S. Amaha, D.G. Austing, Y. Tokura, K. Muraki, K. Ono, and S. Tarucha
Solid State Commun. 119, 183 (2001).
Longitudinal Resistance Anomaly Around the 2/3 Filling Factor Observed in a GaAs/AlGaAs Single Heterostructure
K. Hashimoto, K. Muraki, T. Saku, and Y. Hirayama
Physica B 298, 191 (2001).
Preferred Number of Flipped Spins in Skyrmion Excitation
N. Kumada, A. Sawada, Z.F. Ezawa, H. Azuhata, S. Nagahama, K. Muraki, T. Saku, and Y. Hirayama
Physica B 298, 191 (2001).
Nonequilibrium Population in Fractional Edge States
T. Machida, S. Ishizuka, S. Komiyama, K. Muraki, and Y. Hirayama
Physica B 298, 150 (2001).
Scaling in Fractional Quantum Hall Transitions
T. Machida, S. Ishizuka, S. Komiyama, K. Muraki, and Y. Hirayama
Physica B 298, 182 (2001).
Single Dot and Strongly Coupled Double Dots at High Magnetic Fields
D.G. Austing, H. Tamura, Y. Tokura, K. Muraki, S. Amaha, K. Ono and S. Tarucha
Physica E 10, 112 (2001).
Backgated Layers and Nanostructures
Y. Hirayama, K. Muraki, A. Kawaharazuka, K. Hashimoto, and T. Saku
Physica E 11, 155 (2001).
2000
n(+)-GaAs Back-Gated Double-Quantum-Well Structure with Full Density Control
K. Muraki, N. Kumada, T. Saku, and Y. Hirayama
Jpn. J. Appl. Phys. 39, 2444 (2000). [abstract]
Doubly Enhanced Skyrmions in nu=2 Bilayer Quantum Hall States
N. Kumada, A. Sawada, Z.F. Ezawa, S. Nagahama, H. Azuhata, K. Muraki, T. Saku and Y. Hirayama
J. Phys. Soc. Jpn. 69, 3178 (2000).
Resistance Fluctuations in Integer Quantum-Hall Transitions
T. Machida, S. Ishizuka, K. Muraki, Y. Hirayama, and S. Komiyama
Physica E 6, 152 (2000).
Quantum Coherence and Skyrmion Textures in Bilayer Quantum Hall Systems
Z.F. Ezawa, A. Sawada, K. Muraki, and Y. Hirayama
Physica E 6, 640 (2000).
1999
Interlayer Charge Transfer in Bilayer Quantum Hall States at Various Filling Factors
K. Muraki, T. Saku, Y. Hirayama, N. Kumada, A. Sawada, and Z.F. Ezawa
Solid State Commun. 112, 625 (1999).
Spin Transition of a Two-Dimensional Hole System in the Fractional Quantum Hall Effect
K. Muraki and Y. Hirayama
Phys. Rev. B 59, R2502 (1999). [abstract]
High-Quality Two-Dimensional Electron Gas at an Inverted Undoped Heterointerface
Y. Hirayama, K. Muraki, and T. Saku
Superlattice Microst. 25, 295 (1999).
1998
Re-entrant Behavior of the nu=4/3 Fractional Quantum Hall Effect in a Front-and-Back-Gated 2D Hole Gas
K. Muraki and Y. Hirayama
Physica B 258, 86 (1998).
Effect of Valence Band Structure on the Fractional Quantum Hall Effect of Two-Dimensional Hole Systems
K. Muraki and Y. Hirayama
Physica B 251, 65 (1998).
Photoluminescence from a Modulation-Doped AlGaAs/GaAs Heterointerface Under Cyclotron Resonance
K. Suzuki, K. Saito, K. Muraki, and Y. Hirayama
Phys. Rev. B 58, 15385 (1998).
High-Mobility Two-Dimensional Electron Gas in an Undoped Heterostructure: Mobility Enhancement After Illumination
T. Saku, K. Muraki, and Y. Hirayama
Jpn. J. Appl. Phys. 37, L765 (1998).
Two-Dimensional Electron Gas Formed in a Back-Gated Undoped Heterostructure
Y. Hirayama, K. Muraki, and T. Saku
Appl. Phys. Lett. 72, 1745 (1998).
Quantum Dot Molecules
D.G. Austing, T. Honda, K. Muraki, Y. Tokura, and S. Tarucha
Physica B 251, 206 (1998).
Electronic States in Quantum Dot Atoms and Molecules
S. Tarucha, T. Honda, D.G. Austing, Y. Tokura, K. Muraki, T.H. Oosterkamp, J.W. Janssen, L.P. Kouwenhoven
Physica E 3, 112 (1998).
Metastability of the quantum Hall states in asymmetric two-layer systems
Y. Takagaki, K.-J. Friedland, K. H. Ploog, and K. Muraki
J. Phys.: Condens. Matt. 10, 8305 (1998).
Quantum Hall Effect in Asymmetric Double Quantum Well Systems
Y. Takagaki, K. Muraki, and S. Tarucha
Semocond. Sci. Technol. 13, 296 (1998).
1997
Suppression of AlGaAs/GaAs Superlattice Intermixing by p-type Doping
K. Muraki and Y. Horikoshi
J. Cryst. Growth 175, 162 (1997).
Splitting of Resistance Peaks and Anomalous Hall Plateaus in Asymmetric Double-Quantum-Well Structures
Y. Takagaki, K. Muraki, and S. Tarucha
Phys. Rev. B 56, 1057 (1997).
The Infrared Vibrational Absorption Spectrum of the Si-X Defect Present in Heavily Si Doped GaAs
M. J. Ashwin, R. C. Newman, and K. Muraki
J. Appl. Phys. 82, 137 (1997).
1996
Evidence for Resonant Electron Capture and Charge Buildup in GaAs/AlGaAs Quantum Wells
K. Muraki, A. Fujiwara, S. Fukatsu, Y. Shiraki, and Y. Takahashi
Phys. Rev. B 53, 15477 (1996). [abstract]
Fermi-Level Effect on Ga Self-Diffusion Studied Using (69)GaAs/(69)Ga(71)GaAs Isotope Superlattice
K. Muraki and Y. Horikoshi
Inst. Phys. Conf. Ser. 145, 547 (1996).
1995
Observation of Spatially Indirect Transitions and Accurate Determination of Band Offset Ratio by Excitation Spectroscopy on GaAs/AlGaAs Quantum Wells Lightly Doped with Be Acceptors
K. Muraki, S. Fukatsu, Y. Shiraki, and Y. Takahashi
J. Cryst. Growth 150, 49 (1995).
Enhancement of Nonradiative Recombination Due to Resonant Electron Capture in AlGaAs/GaAs Quantum Well Structures
A. Fujiwara, K. Muraki, S. Fukatsu, Y. Shiraki, and R. Ito
Phys. Rev. B 51, 14324 (1995).
Growth of InGaAs/GaAs Strained Quantum Wells on GaAs (111)B Substrates and Continuous Wave Operation of (111)B-Oriented InGaAs Strained Quantum Well Lasers
T. Takeuchi, K. Muraki, Y. Hanamaki, S. Fukatsu, N. Yamada, N. Ogasawara, N. Mikoshiba, and Y. Shiraki
J. Cryst. Growth 150, 1338 (1995).
1994
Enhancement of Free-to-Bound Transitions Due to Resonant Electron Capture in Be-Doped AlGaAs/GaAs Quantum Well
K. Muraki, Y. Takahashi, A. Fujiwara, S. Fukatsu, and Y. Shiraki
Solid State Electron 37, 1247 (1994).
Valence-Subband Level Crossing in GaAs/GaAsP Strained-Barrier Quantum Well Structures Observed by Circularly-Polarized Photoluminescence Excitation Spectroscopy
H. Yaguchi, K. Ota, Y. Takahashi, K. Muraki, K. Onabe, Y. Shiraki, and R. Ito
Solid State Electron 37, 915 (1994).
Direct Observation of Exciton Localization in a GaAs/AlGaAs Quantum Well
Y. Takahashi, S.S. Kano, K. Muraki, S. Fukatsu, Y. Shiraki, and R. Ito
Appl. Phys. Lett. 64, 1845 (1994).
Time-of-Flight Measurement of Carrier Transport and Carrier Collection in Strained SiGe/Si Quantum Wells
S. Fukatsu, A. Fujiwara, K. Muraki, Y. Takahashi, and Y. Shiraki
J. Vac. Sci. Technol. B 12, 1156 (1994).
1993
Surface Segregation of In Atoms and Its Influence on the Quantized Levels in InGaAs/GaAs Quantum Wells
K. Muraki, S. Fukatsu, Y. Shiraki, and R. Ito
J. Cryst. Growth 127, 546 (1993).
Fast Lateral Transport of Excitons in a GaAs/AlGaAs Quantum Wells
Y. Takahashi, K. Muraki, S. Fukatsu, S.S. Kano, Y. Shiraki, and R. Ito
Jpn. J. Appl. Phys. 32, 5586 (1993).
In-Plane Transport of Excitons in Quantum Well Structures
Y. Takahashi, K. Muraki, S. Fukatsu, S.S. Kano, Y. Shiraki, and R. Ito
Solid State Commun. 88, 677 (1993).
Observation of the Valence-Subband Level Crossing in GaAs/GaAsP Strained-Barrier Quantum Well Structures Using Circularly-Polarized Photoluminescence Excitation Spectroscopy
K. Ota, H. Yaguchi, K. Onabe, R. Ito, Y. Takahashi, K. Muraki, and Y. Shiraki
Appl. Phys. Lett. 63, 946 (1993).
1992
Surface Segregation of In Atoms During Molecular Beam Epitaxy and Its Influence on the Energy Levels in InGaAs/GaAs Quantum Wells
K. Muraki, S. Fukatsu, Y. Shiraki, and R. Ito
Appl. Phys. Lett. 61, 557 (1992). [abstract]
Anomalies in Photoluminescence Linewidth of InGaAs/GaAs Strained-Layer Quantum Wells
K. Muraki, S. Fukatsu, Y. Shiraki, and R. Ito
Surf. Sci. 267, 107 (1992).
Two-Dimensional Exciton Dynamics in InGaAs/GaAs Quantum Wells
Y. Takahashi, Y. Owa, S.S. Kano, K. Muraki, S. Fukatsu, Y. Shiraki, and R. Ito
Appl. Phys. Lett. 60, 213 (1992).