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تسجيل مستخدم جديدPseudospin Soliton in the $ u=1$ Bilayer Quantum Hall State
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We investigate a domain structure of pseudospins, a soliton lattice in the bilayer quantum Hall state at total Landau level filling factor $ u =1$, in a tilted magnetic field, where the pseudospin represents the layer degree of freedom. An anomalous peak in the magnetoresistance $R_{xx}$ appears at the transition point between the commensurate and incommensurate phases. The $R_{xx}$ at the peak is highly anisotropic for the angle between the in-plain magnetic field $B_parallel $ and the current, and indicates a formation of the soliton lattice aligned parallel to $B_parallel $. Temperature dependence of the $R_{xx}$ peak reveals that the dissipation is caused by thermal fluctuations of pseudospin solitons. We construct a phase diagram of the bilayer $ u =1$ system as a function of $B_parallel$ and the total electron density. We also study effects of density imbalance between the two layers.
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اقرأ أيضاً
We revisit the physics of electron gas bilayers in the quantum Hall regime [Nature, 432 (2004) 691; Science, 305 (2004) 950], where transport and tunneling measurements provided evidence of a superfluid phase being present in the system. Previously,
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rom the bilayer balanced density state to the monolayer state. Even a sample with 33 K tunneling gap shows the same activation energy anomaly reported by Murphy {it et al.}. We discuss a possible relation between our experimental results and the quantum Hall ferromagnet of spins and pseudospins.
The Hall-plateau width and the activation energy were measured in the bilayer quantum Hall state at filling factor u=2, 1 and 2/3, by changing the total electron density and the density ratio in the two quantum wells. Their behavior are remarkably d
ifferent from one to another. The u=1 state is found stable over all measured range of the density difference, while the u=2/3$ state is stable only around the balanced point. The u=2 state, on the other hand, shows a phase transition between these two types of the states as the electron density is changed.
We have measured the Hall-plateau width and the activation energy of the bilayer quantum Hall (BLQH) states at the Landau-level filling factor $ u=1$ and 2 by tilting the sample and simultaneously changing the electron density in each quantum well. T
he phase transition between the commensurate and incommensurate states are confirmed at $ u =1$ and discovered at $ u =2$. In particular, three different $ u =2$ BLQH states are identified; the compound state, the coherent commensurate state, and the coherent incommensurate state.
We have studied the fractional and integer quantum Hall (QH) effects in a high-mobility double-layer two-dimensional electron system. We have compared the stability of the QH state in balanced and unbalanced double quantum wells. The behavior of the
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