TY - JOUR
T1 - Spin susceptibility and effective mass of two-dimensional electrons in Mgx Zn1-x O/ZnO heterostructures
AU - Tsukazaki, A.
AU - Ohtomo, A.
AU - Kawasaki, M.
AU - Akasaka, S.
AU - Yuji, H.
AU - Tamura, K.
AU - Nakahara, K.
AU - Tanabe, T.
AU - Kamisawa, A.
AU - Gokmen, T.
AU - Shabani, J.
AU - Shayegan, M.
PY - 2008/12/1
Y1 - 2008/12/1
N2 - We report measurements of the spin susceptibility and the electron effective mass for two-dimensional electrons confined at the interfaces of Mgx Zn1-x O/ZnO single heterostructures (x=0.05, 0.08, and 0.11), grown by molecular-beam epitaxy on (0001) ZnO substrates. By tuning the built-in polarization through control of the barrier composition, the electron density was systematically varied in the range of 5.6× 1011 -1.6× 1012 cm-2, corresponding to a range of 3.1≤ rs ≤5.2, where rs is the average electron spacing measured in units of the effective Bohr radius. We used the coincidence technique, where crossings of the spin-split Landau levels occur at critical tilt angles of magnetic field, to evaluate the spin susceptibility. In addition, we determined the effective mass from the temperature dependence of the Shubnikov-de Haas oscillations measured at the coincidence conditions. The susceptibility and the effective mass both gradually increase with decreasing electron density, reflecting the role of electron-electron interaction.
AB - We report measurements of the spin susceptibility and the electron effective mass for two-dimensional electrons confined at the interfaces of Mgx Zn1-x O/ZnO single heterostructures (x=0.05, 0.08, and 0.11), grown by molecular-beam epitaxy on (0001) ZnO substrates. By tuning the built-in polarization through control of the barrier composition, the electron density was systematically varied in the range of 5.6× 1011 -1.6× 1012 cm-2, corresponding to a range of 3.1≤ rs ≤5.2, where rs is the average electron spacing measured in units of the effective Bohr radius. We used the coincidence technique, where crossings of the spin-split Landau levels occur at critical tilt angles of magnetic field, to evaluate the spin susceptibility. In addition, we determined the effective mass from the temperature dependence of the Shubnikov-de Haas oscillations measured at the coincidence conditions. The susceptibility and the effective mass both gradually increase with decreasing electron density, reflecting the role of electron-electron interaction.
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U2 - 10.1103/PhysRevB.78.233308
DO - 10.1103/PhysRevB.78.233308
M3 - Article
AN - SCOPUS:58149142821
SN - 1098-0121
VL - 78
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 23
M1 - 233308
ER -