Klochan, O., Micolich, A. P., Ho, L. H., Hamilton, A. R., Muraki, K., Hirayama, Y.
We study the Zeeman splitting in induced ballistic 1D quantum wires aligned along the [233] and [011] axes of a high mobility (311)A undoped heterostructure. Our data shows that the g-factor...
Kumada, N., Kamada, T., Miyashita, S., Hirayama, Y., Fujisawa, T.
We demonstrate an alternative nuclear spin resonance using radio frequency (RF) electric field (nuclear electric resonance: NER) instead of magnetic field. The NER is based on the electronic control...
The Quantum Hall Transition in Real Space: From Localized to Extended States (2008)
Hashimoto, K., Sohrmann, C., Wiebe, J., Inaoka, T., Meier, F., Hirayama, Y., ...
Using scanning tunneling spectroscopy in ultra-high vacuum at low temperature (T = 0.3 K) and high magnetic fields (B < 12 T), we directly probe electronic wave functions across an integer quantum...
A gate-defined silicon quantum dot molecule (2008)
Liu, H. W., Fujisawa, T., Inokawa, H., Ono, Y., Fujiwara, A., Hirayama, Y.
We report electron transport measurements of a silicon double dot formed in multi-gated metal-oxide-semiconductor structures with a 15-nm-thick silicon-on-insulator layer. Tunable tunnel coupling...
Boundary-mediated electron-electron interactions in quantum point contacts (2008)
Renard, Vincent, Tkachenko, O. A., Tkachenko, V.A., Ota, T., Kumada, N., ...
An unusual increase of the conductance with temperature is observed in clean quantum point contacts for conductances larger than 2e^2/h. At the same time a positive magnetoresistance arises at high...
Boundary-mediated electron-electron interactions in quantum point contacts (2008)
Renard, Vincent, Tkachenko, O. A., Tkachenko, V.A., Ota, T., Kumada, N., ...
An unusual increase of the conductance with temperature is observed in clean quantum point contacts for conductances larger than 2e^2/h. At the same time a positive magnetoresistance arises at high...
Boundary-mediated electron-electron interactions in quantum point contacts (2008)
Renard, Vincent, Tkachenko, O. A., Tkachenko, V.A., Ota, T., Kumada, N., ...
An unusual increase of the conductance with temperature is observed in clean quantum point contacts for conductances larger than 2e^2/h. At the same time a positive magnetoresistance arises at high...
Boundary-mediated electron-electron interactions in quantum point contacts (2008)
Renard, Vincent, Tkachenko, O. A., Tkachenko, V.A., Ota, T., Kumada, N., ...
An unusual increase of the conductance with temperature is observed in clean quantum point contacts for conductances larger than 2e^2/h. At the same time a positive magnetoresistance arises at high...
Boundary-mediated electron-electron interactions in quantum point contacts (2008)
Renard, Vincent Thomas Francois, Tkachenko, O. A., Tkachenko, V. A., Ota, T., Kumada, N., ...
An unusual increase of the conductance with temperature is observed in clean quantum point contacts for conductances larger than 2e^2/h. At the same time a positive magnetoresistance arises at high...
The Quantum Hall transition in real space: From localized to extended states (2008)
Hashimoto, K, Sohrmann, C, Wiebe, J, Inaoka, T, Meier, F, Hirayama, Y, ...
Two-dimensional electron systems (2DES) are considered as paradigms for the study of quantum phase transitions. Three prominent examples are the disorder-driven metal-insulator transition , the...
Pseudospin Soliton in the $\nu=1$ Bilayer Quantum Hall State (2007)
Fukuda, A., Terasawa, D., Morino, M., Iwata, K., Kozumi, S., Kumada, N., ...
We investigate a domain structure of pseudospins, a soliton lattice in the bilayer quantum Hall state at total Landau level filling factor $\nu =1$, in a tilted magnetic field, where the pseudospin...
Ota, T., Yusa, G., Kumada, N., Miyashita, S., Fujisawa, T., Hirayama, Y.
We study decoherence of nuclear spins in a GaAs quantum well structure using resistively detected nuclear magnetic resonance. The transverse decoherence time T2 of 75As nuclei is estimated from...
Kumada, N., Iwata, K., Tagashira, K., Shimoda, Y., Muraki, K., Hirayama, Y., ...
We study effects of tilted magnetic fields on energy levels in a double-quantum-well (DQW) system, focusing on the coupling of subbands and Landau levels (LLs). The subband-LL coupling induces...
Pauli-Spin-Blockade Transport through a Silicon Double Quantum Dot (2007)
Liu, H. W., Fujisawa, T., Ono, Y., Inokawa, H., Fujiwara, A., Takashina, K., ...
We present measurements of resonant tunneling through discrete energy levels of a silicon double quantum dot formed in a thin silicon-on-insulator layer. In the absence of piezoelectric phonon...
NMR Evidence for Spin Canting in a Bilayer nu = 2 Quantum Hall System (2007)
Kumada, N., Muraki, K., Hirayama, Y.
We investigate the electron spin states in the bilayer quantum Hall system at total Landau level filling factor nu =2 exploiting current-pumped and resistively detected NMR. The measured Knight...
Ota, T., Yusa, G., Kumada, N., Miyashita, S., Hirayama, Y.
We study the nuclear spin population in a GaAs quantum well structure and demonstrate its initialization using an all-electrical nuclear magnetic resonance (NMR) device. In our device, nuclear spins...
Nuclear Spins in a Nanoscale Device for Quantum Information Processing (2006)
Ozdemir, S. K., Miranowicz, A., Ota, T., Yusa, G., Imoto, N., Hirayama, Y.
Coherent oscillations between any two levels from four nuclear spin states of I=3/2 have been demonstrated in a nanometre-scale NMR semiconductor device, where nuclear spins are all-electrically...
Anomalous Resistance Ridges Along Filling Factor $\nu = 4i$ (2006)
Takashina, K., Brun, M., Ota, T., Maude, D. K., Fujiwara, A., Ono, Y., ...
We report anomalous structure in the magnetoresistance of SiO$_2$/Si(100)/SiO$_2$ quantum wells. When Landau levels of opposite valleys are driven through coincidence at the Fermi level, the...
Ballistic transport in induced one-dimensional hole systems (2006)
Klochan, O., Clarke, W. R., Danneau, R., Micolich, A. P., Ho, L. H., Hamilton, A. R., ...
We have fabricated and studied a ballistic one-dimensional p-type quantum wire using an undoped AlGaAs/GaAs heterostructure. The absence of modulation doping eliminates remote ionized impurity...
Nanometre-scale nuclear-spin device for quantum information processing (2006)
Hirayama, Y., Miranowicz, A., Ota, T., Yusa, G., Muraki, K., Ozdemir, S. K., ...
We have developed semiconductor point contact devices in which nuclear spins in a nanoscale region are coherently controlled by all-electrical methods. Different from the standard nuclear-magnetic...
Valley Polarization in Si(100) at Zero Magnetic Field (2006)
Takashina, K., Ono, Y., Fujiwara, A., Takahashi, Y., Hirayama, Y.
The valley splitting, which lifts the degeneracy of the lowest two valley states in a SiO$_2$/(100)Si/SiO$_2$ quantum well is examined through transport measurements. We demonstrate that the valley...
Fukuda, A, Sawada, A, Kozumi, S, Terasawa, D, Shimoda, Y, Ezawa, ZF, ...
Non-local Control of the Kondo Effect in a Double Quantum Dot-Quantum Wire Coupled System (2006)
Sasaki, S., Kang, S., Kitagawa, K., Yamaguchi, M., Miyashita, S., Maruyama, T., ...
We have performed low-temperature transport measurements on a double quantum dot-quantum wire coupled device and demonstrated non-local control of the Kondo effect in one dot by manipulating the...
Fukuda, A., Sawada, A., Kozumi, S., Terasawa, D., Shimoda, Y., Ezawa, Z. F., ...
Magnetotransport properties are investigated in the bilayer quantum Hall state at the total filling factor $\nu=2$. We measured the activation energy elaborately as a function of the total electron...
Optical probing of composite fermions in a two-dimensional electron gas (2006)
Byszewski, M., Chwalisz, B., Maude, D. K., Sadowski, M. L., Potemski, M., Saku, T., ...
Optically detected cyclotron resonance in a high mobility 2D electron gas (2006)
Moreau, S., Byszewski, M., Sadowski, M. L., Potemski, M., Studenikin, S. A., Austing, G., ...
We study the properties of high mobility GaAs/GaAlAs quantum well structure by monitoring the microwave induced changes in the low-temperature photoluminescence of the 2DEG as a function of the...
Pauli spin blockade in cotunneling transport through a double quantum dot (2005)
Liu, H. W., Fujisawa, T., Hayashi, T., Hirayama, Y.
We study spin correlation in a double quantum dot containing a few electrons in each dot (around 10). Clear current rectification with negative differential conductance is observed in the cotunneling...
Electrical pump-and-probe study of spin singlet-triplet relaxation in a quantum dot (2005)
Sasaki, S., Fujisawa, T., Hayashi, T., Hirayama, Y.
Spin relaxation from a triplet excited state to a singlet ground state in a semiconductor quantum dot is studied by employing an electrical pump-and-probe method. Spin relaxation occurs via...
Optically detected cyclotron resonance in a high mobility (2005)
Moreau, S., Byszewski, M., Sadowski, M. L., Potemski, M., Studenikin, S., Austing, G., ...
Kumada, N., Muraki, K., Hashimoto, K., Hirayama, Y.
The nuclear-spin-relaxation rate 1/T_1 has been measured in a bilayer electron system at and around total Landau level filling factor nu =1. The measured 1/T_1, which probes electron spin...
Background charge fluctuation in a GaAs quantum dot device (2004)
Jung, S. W., Fujisawa, T., Jeong, Y. H., Hirayama, Y.
We investigate background charge fluctuation in a GaAs quantum dot device by measuring 1/f noise in the single-electron tunneling current through the dot. The current noise is understood as...
Simultaneous Excitation of Spins and Pseudospins in the Bilayer $\nu=1$ Quantum Hall State (2004)
Terasawa, D., Morino, M., Nakada, K., Kozumi, S., Sawada, A., Ezawa, Z. F., ...
The tilting angular dependence of the energy gap was measured in the bilayer quantum Hall state at the Landau level filling $\nu=1$ by changing the density imbalance between the two layers. The...
Shot Noise Suppression at Non-integer Conductance Plateaus in a Quantum Point Contact (2003)
Kim, N. Y., Oliver, W. D., Yamamoto, Y., Hirayama, Y.
We study non-equilibrium differential conductance and current fluctuations in a single quantum point contact. The two-terminal electrical transport properties -- differential conductance and shot...
Generation of maximum spin entanglement induced by cavity field in quantum-dot systems (2002)
Miranowicz, A., Ozdemir, S. K., Liu, Yu-xi, Koashi, M., Imoto, N., Hirayama, Y.
Equivalent-neighbor interactions of the conduction-band electron spins of quantum dots in the model of Imamoglu et al. [Phys. Rev. Lett. 83, 4204 (1999)] are analyzed. Analytical solution and its...
Phase Transitions in the Bilayer $\nu =2/3$ Quantum Hall Effect (2001)
Kumada, N., Terasawa, D., Shimoda, Y., Azuhata, H., Sawada, A., Ezawa, Z. F., ...
We measured the magnetoresistance of bilayer quantum Hall (QH) effects at the fractional filling factor $\nu =2/3$ by changing the total electron density and the density difference between two...
Electrically-Controlled Nuclear Spin Polarization and Relaxation by Quantum-Hall states (2001)
Hashimoto, K., Muraki, K., Saku, T., Hirayama, Y.
We investigate interactions between electrons and nuclear spins by using the resistance (Rxx) peak which develops near filling factor n = 2/3 as a probe. By temporarily tuning n to a different value,...
Miranowicz, A., Ozdemir, S. K., Koashi, M., Imoto, N., Hirayama, Y.
Time evolution of entanglement of N quantum dots is analyzed within the spin-1/2 van der Waals (or Lipkin-Meshkov-Glick) XY model. It is shown that, for a single dot initially excited and...
Doubly Enhanced Skyrmions in $\nu =2$ Bilayer Quantum Hall States (2000)
Kumada, N., Sawada, A., Ezawa, Z. F., Nagahama, S., Azuhata, H., Muraki, K., ...
By tilting the samples in the magnetic field, we measured and compared the Skyrmion excitations in the bilayer quantum Hall (QH) state at the Landau-level filling factor $\nu =2$ and in the monolayer...
"Interlayer charge transfer in bilayer quantum Hall states at various filling factors." (1999)
熊田, 倫雄, Kumada, N, 澤田, 安樹, Sawada, A, Muraki, K, Saku, T, ...
Solid State Commun.B 112, 625-629, (1999)収録。
"Interlayer charge transfer in bilayer quantum Hall states at various filling factors." (1999)
熊田, 倫雄, Kumada, N, 澤田, 安樹, Sawada, A, Muraki, K, Saku, T, ...
Solid State Commun.B 112, 625-629, (1999)収録。
Layer Thickness Dependence of Magnetic Properties in Mn/Al Multilayers. (1998)
Hirayama, Y., Takeuchi, T., Futamoto, M.
Examination between the relationships of the magnetic properties and the film structure of mn/al multilayers was performed by changing the thickness of mn and al layers. it can be seen, by x-ray...
Thesis (Ph. D.)--Cranfield University, 1998.
Kobayashi, T, Nishizawa, M, Hirayama, Y, Kobayashi, E, Hino, O
The Eker rat hereditary renal carcinoma (RC) is an excellent example of a Mendelian dominant predisposition to a specific cancer in an experimental animal. We recently reported that a germline...
Seiki, M, Hattori, S, Hirayama, Y, Yoshida, M
Human retrovirus adult T-cell leukemia virus (ATLV) has been shown to be closely associated with human adult T-cell leukemia (ATL) [Yoshida, M., Miyoshi, I. & Hinuma, Y. (1982) Proc. Natl. Acad. Sci....
Kuniyasu, A, Kawano, S, Hirayama, Y, Ji, Y H, Xu, K, Ohkura, M, ...
A peptide toxin isolated from the Chinese scorpion Buthus martensi Karsch (BmK-PL) stimulated Ca2+-release channel activity in both triad membranes and reconstituted ryanodine receptors partially...
Activation mechanism of Ca(2+)-sensitive transient outward current in rabbit ventricular myocytes.
Kawano, S, Hirayama, Y, Hiraoka, M
1. The mechanism of activation of the Ca(2+)-sensitive and 4-aminopyridine (4-AP)-insensitive transient outward current, I(to)(Ca), was examined in single rabbit ventricular myocytes using the...
Kobayashi, T, Nishizawa, M, Hirayama, Y, Kobayashi, E, Hino, O
The Eker rat hereditary renal carcinoma (RC) is an excellent example of a Mendelian dominant predisposition to a specific cancer in an experimental animal. We recently reported that a germline...
Seiki, M, Hattori, S, Hirayama, Y, Yoshida, M
Human retrovirus adult T-cell leukemia virus (ATLV) has been shown to be closely associated with human adult T-cell leukemia (ATL) [Yoshida, M., Miyoshi, I. & Hinuma, Y. (1982) Proc. Natl. Acad. Sci....
Activation mechanism of Ca(2+)-sensitive transient outward current in rabbit ventricular myocytes.
Kawano, S, Hirayama, Y, Hiraoka, M
1. The mechanism of activation of the Ca(2+)-sensitive and 4-aminopyridine (4-AP)-insensitive transient outward current, I(to)(Ca), was examined in single rabbit ventricular myocytes using the...
Kuniyasu, A, Kawano, S, Hirayama, Y, Ji, Y H, Xu, K, Ohkura, M, ...
A peptide toxin isolated from the Chinese scorpion Buthus martensi Karsch (BmK-PL) stimulated Ca2+-release channel activity in both triad membranes and reconstituted ryanodine receptors partially...
Accessory cell functions of dendritic cells and macrophages in the thymic T-cell response to Con A.
Hirayama, Y, Inaba, K, Komatsubara, S, Yoshida, K, Kawai, J, Naito, K, ...
Accessory cell (A cell) functions of splenic dendritic cells (DC) and peritoneal macrophages (M phi) were investigated in the Con A-stimulated proliferative response of thymic T cells. DC were more...
Ramnarine, S I, Hirayama, Y, Barnes, P J, Rogers, D F
1. We characterized the tachykinin receptor(s) mediating 'sensory-efferent' neural control of release of 35SO4-labelled macromolecules (mucus) from ferret trachea in vitro in Ussing chambers using...
Hirayama, Y., Lei, Y. H., Barnes, P. J., Rogers, D. F.
1. We compared the effects of two novel tachykinin receptor antagonists, FK888 (selective at the tachykinin NK1 receptor) and FK224 (dual antagonist at NK1 and NK2 tachykinin receptors) on...
Angiotensin converting enzyme (ACE) inhibitor-induced cough and substance P.
Tomaki, M., Ichinose, M., Miura, M., Hirayama, Y., Kageyama, N., Yamauchi, H., ...
BACKGROUND: Angiotensin converting enzyme (ACE) inhibitors cause coughing in 5-10% of patients, but the exact mechanisms of this effect are still unclear. In the airways ACE degrades substance P so...