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F M Peeters - One of the best experts on this subject based on the ideXlab platform.
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graphene hall Bar with an asymmetric pn junction
arXiv: Mesoscale and Nanoscale Physics, 2013Co-Authors: S P Milovanovic, Ramezani M Masir, F M PeetersAbstract:We investigated the magnetic field dependence of the Hall and the bend resistances in the ballistic regime for a single layer graphene Hall Bar Structure containing a pn-junction. When both regions are n-type the Hall resistance dominates and Hall type of plateaus are formed. These plateaus occur as a consequence of the restriction on the angle imposed by Snell's law allowing only electrons with a certain initial angles to transmit though the potential step. The size of the plateau and its position is determined by the position of the potential interface as well as the value of the applied potential. When the second region is p-type the bend resistance dominates which is asymmetric in field due to the presence of snake states. Changing the position of the pn-interface in the Hall Bar strongly affects these states and therefore the bend resistance is also changed. Changing the applied potential we observe that the bend resistance exhibits a peak around the charge-neutrality point (CNP) which is independent of the position of the pn-interface, while the Hall resistance shows a sign reversal when the CNP is crossed, which is in very good agreement with a recent experiment [J. R. Williams et al., Phys. Rev. Lett. 107, 046602(2011)].
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bilayer graphene hall Bar with a pn junction
Journal of Applied Physics, 2013Co-Authors: S P Milovanovic, Ramezani M Masir, F M PeetersAbstract:We investigate the magnetic field dependence of the Hall and the bend resistances for a ballistic Hall Bar Structure containing a pn-junction sculptured from a bilayer of graphene. The electric response is obtained using the billiard model, and we investigate the cases of bilayer graphene with and without a band gap. Two different conduction regimes are possible: (i) both sides of the junction have the same carrier type and (ii) one side of the junction is n-type while the other one is p-type. The first case shows Hall plateau-like features in the Hall resistance that fade away as the band gap opens. The second case exhibits a bend resistance that is asymmetric in magnetic field as a consequence of snake states along the pn-interface, where the maximum is shifted away from zero magnetic field.
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graphene hall Bar with an asymmetric pn junction
Journal of Applied Physics, 2013Co-Authors: S P Milovanovic, Ramezani M Masir, F M PeetersAbstract:We investigated the magnetic field dependence of the Hall and the bend resistances in the ballistic regime for a single layer graphene Hall Bar Structure containing a pn-junction. When both regions are n-type the Hall resistance dominates and Hall type of plateaus are formed. These plateaus occur as a consequence of the restriction on the angle imposed by Snell's law allowing only electrons with a certain initial angles to transmit though the potential step. The size of the plateau and its position is determined by the position of the potential interface as well as the value of the applied potential. When the second region is p-type, the bend resistance dominates, which is asymmetric in field due to the presence of snake states. Changing the position of the pn-interface in the Hall Bar strongly affects these states and therefore the bend resistance is also changed. Changing the applied potential, we observe that the bend resistance exhibits a peak around the charge-neutrality point (CNP), which is independent of the position of the pn-interface, while the Hall resistance shows a sign reversal when the CNP is crossed, which is in very good agreement with a recent experiment [J. R. Williams and C. M. Marcus, Phys. Rev. Lett. 107, 046602 (2011)].
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snake states and klein tunneling in a graphene hall Bar with a pn junction
Applied Physics Letters, 2012Co-Authors: Michael Barbier, G Papp, F M PeetersAbstract:The Hall (RH) and bend (RB) resistances of a graphene Hall Bar Structure containing a pn-junction are calculated when in the ballistic regime. The simulations are done using the billiard model. Introducing a pn-junction—dividing the Hall Bar geometry in two regions—leads to two distinct regimes exhibiting very different physics: (1) both regions are of n-type and (2) one region is n-type and the other p-type. In regime (1), a “Hall plateau”—an enhancement of the resistance—appears for RH. On the other hand, in regime (2), we found a negative RH, which approaches zero for large B. The bend resistance is highly asymmetric in regime (2) and the resistance increases with increasing magnetic field B in one direction while it reduces to zero in the other direction.
Martin C Smith - One of the best experts on this subject based on the ideXlab platform.
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modelling the galactic Bar using ogle ii red clump giant stars
Monthly Notices of the Royal Astronomical Society, 2007Co-Authors: N J Rattenbury, Shude Mao, T Sumi, Martin C SmithAbstract:Red clump giant (RCG) stars can be used as distance indicators to trace the mass distribution of the Galactic Bar. We use RCG stars from 44 bulge fields from the OGLE-II microlensing collaboration data base to constrain analytic triaxial models for the Galactic Bar. We find the Bar major-axis is oriented at an angle of 24 degrees-27 degrees to the Sun-Galactic Centre line-of-sight. The ratio of semimajor and semiminor Bar axis scalelengths in the Galactic plane x(0), y(0), and vertical Bar scalelength z(0), is x(0) : y(0) : z(0) = 10 : 3.5 : 2.6, suggesting a slightly more prolate Bar Structure than the working model of Gerhard which gives the scalelength ratios as x(0) : y(0) : z(0) = 10 : 4 : 3.
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modelling the galactic Bar using ogle ii red clump giant stars
arXiv: Astrophysics, 2007Co-Authors: N J Rattenbury, Shude Mao, T Sumi, Martin C SmithAbstract:Red clump giant stars can be used as distance indicators to trace the mass distribution of the Galactic Bar. We use RCG stars from 44 bulge fields from the OGLE-II microlensing collaboration database to constrain analytic tri-axial models for the Galactic Bar. We find the Bar major axis is oriented at an angle of 24 - 27 degrees to the Sun-Galactic centre line-of-sight. The ratio of semi-major and semi-minor Bar axis scale lengths in the Galactic plane x_0, y_0, and vertical Bar scale length z_0, is x_0 : y_0 : z_0 = 10 : 3.5 : 2.6, suggesting a slightly more prolate Bar Structure than the working model of Gerhard (2002) which gives the scale length ratios as x_0 : y_0 : z_0 = 10 : 4 : 3 .
S P Milovanovic - One of the best experts on this subject based on the ideXlab platform.
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graphene hall Bar with an asymmetric pn junction
arXiv: Mesoscale and Nanoscale Physics, 2013Co-Authors: S P Milovanovic, Ramezani M Masir, F M PeetersAbstract:We investigated the magnetic field dependence of the Hall and the bend resistances in the ballistic regime for a single layer graphene Hall Bar Structure containing a pn-junction. When both regions are n-type the Hall resistance dominates and Hall type of plateaus are formed. These plateaus occur as a consequence of the restriction on the angle imposed by Snell's law allowing only electrons with a certain initial angles to transmit though the potential step. The size of the plateau and its position is determined by the position of the potential interface as well as the value of the applied potential. When the second region is p-type the bend resistance dominates which is asymmetric in field due to the presence of snake states. Changing the position of the pn-interface in the Hall Bar strongly affects these states and therefore the bend resistance is also changed. Changing the applied potential we observe that the bend resistance exhibits a peak around the charge-neutrality point (CNP) which is independent of the position of the pn-interface, while the Hall resistance shows a sign reversal when the CNP is crossed, which is in very good agreement with a recent experiment [J. R. Williams et al., Phys. Rev. Lett. 107, 046602(2011)].
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bilayer graphene hall Bar with a pn junction
Journal of Applied Physics, 2013Co-Authors: S P Milovanovic, Ramezani M Masir, F M PeetersAbstract:We investigate the magnetic field dependence of the Hall and the bend resistances for a ballistic Hall Bar Structure containing a pn-junction sculptured from a bilayer of graphene. The electric response is obtained using the billiard model, and we investigate the cases of bilayer graphene with and without a band gap. Two different conduction regimes are possible: (i) both sides of the junction have the same carrier type and (ii) one side of the junction is n-type while the other one is p-type. The first case shows Hall plateau-like features in the Hall resistance that fade away as the band gap opens. The second case exhibits a bend resistance that is asymmetric in magnetic field as a consequence of snake states along the pn-interface, where the maximum is shifted away from zero magnetic field.
-
graphene hall Bar with an asymmetric pn junction
Journal of Applied Physics, 2013Co-Authors: S P Milovanovic, Ramezani M Masir, F M PeetersAbstract:We investigated the magnetic field dependence of the Hall and the bend resistances in the ballistic regime for a single layer graphene Hall Bar Structure containing a pn-junction. When both regions are n-type the Hall resistance dominates and Hall type of plateaus are formed. These plateaus occur as a consequence of the restriction on the angle imposed by Snell's law allowing only electrons with a certain initial angles to transmit though the potential step. The size of the plateau and its position is determined by the position of the potential interface as well as the value of the applied potential. When the second region is p-type, the bend resistance dominates, which is asymmetric in field due to the presence of snake states. Changing the position of the pn-interface in the Hall Bar strongly affects these states and therefore the bend resistance is also changed. Changing the applied potential, we observe that the bend resistance exhibits a peak around the charge-neutrality point (CNP), which is independent of the position of the pn-interface, while the Hall resistance shows a sign reversal when the CNP is crossed, which is in very good agreement with a recent experiment [J. R. Williams and C. M. Marcus, Phys. Rev. Lett. 107, 046602 (2011)].
N J Rattenbury - One of the best experts on this subject based on the ideXlab platform.
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modelling the galactic Bar using ogle ii red clump giant stars
Monthly Notices of the Royal Astronomical Society, 2007Co-Authors: N J Rattenbury, Shude Mao, T Sumi, Martin C SmithAbstract:Red clump giant (RCG) stars can be used as distance indicators to trace the mass distribution of the Galactic Bar. We use RCG stars from 44 bulge fields from the OGLE-II microlensing collaboration data base to constrain analytic triaxial models for the Galactic Bar. We find the Bar major-axis is oriented at an angle of 24 degrees-27 degrees to the Sun-Galactic Centre line-of-sight. The ratio of semimajor and semiminor Bar axis scalelengths in the Galactic plane x(0), y(0), and vertical Bar scalelength z(0), is x(0) : y(0) : z(0) = 10 : 3.5 : 2.6, suggesting a slightly more prolate Bar Structure than the working model of Gerhard which gives the scalelength ratios as x(0) : y(0) : z(0) = 10 : 4 : 3.
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modelling the galactic Bar using ogle ii red clump giant stars
arXiv: Astrophysics, 2007Co-Authors: N J Rattenbury, Shude Mao, T Sumi, Martin C SmithAbstract:Red clump giant stars can be used as distance indicators to trace the mass distribution of the Galactic Bar. We use RCG stars from 44 bulge fields from the OGLE-II microlensing collaboration database to constrain analytic tri-axial models for the Galactic Bar. We find the Bar major axis is oriented at an angle of 24 - 27 degrees to the Sun-Galactic centre line-of-sight. The ratio of semi-major and semi-minor Bar axis scale lengths in the Galactic plane x_0, y_0, and vertical Bar scale length z_0, is x_0 : y_0 : z_0 = 10 : 3.5 : 2.6, suggesting a slightly more prolate Bar Structure than the working model of Gerhard (2002) which gives the scale length ratios as x_0 : y_0 : z_0 = 10 : 4 : 3 .
Ramezani M Masir - One of the best experts on this subject based on the ideXlab platform.
-
graphene hall Bar with an asymmetric pn junction
arXiv: Mesoscale and Nanoscale Physics, 2013Co-Authors: S P Milovanovic, Ramezani M Masir, F M PeetersAbstract:We investigated the magnetic field dependence of the Hall and the bend resistances in the ballistic regime for a single layer graphene Hall Bar Structure containing a pn-junction. When both regions are n-type the Hall resistance dominates and Hall type of plateaus are formed. These plateaus occur as a consequence of the restriction on the angle imposed by Snell's law allowing only electrons with a certain initial angles to transmit though the potential step. The size of the plateau and its position is determined by the position of the potential interface as well as the value of the applied potential. When the second region is p-type the bend resistance dominates which is asymmetric in field due to the presence of snake states. Changing the position of the pn-interface in the Hall Bar strongly affects these states and therefore the bend resistance is also changed. Changing the applied potential we observe that the bend resistance exhibits a peak around the charge-neutrality point (CNP) which is independent of the position of the pn-interface, while the Hall resistance shows a sign reversal when the CNP is crossed, which is in very good agreement with a recent experiment [J. R. Williams et al., Phys. Rev. Lett. 107, 046602(2011)].
-
bilayer graphene hall Bar with a pn junction
Journal of Applied Physics, 2013Co-Authors: S P Milovanovic, Ramezani M Masir, F M PeetersAbstract:We investigate the magnetic field dependence of the Hall and the bend resistances for a ballistic Hall Bar Structure containing a pn-junction sculptured from a bilayer of graphene. The electric response is obtained using the billiard model, and we investigate the cases of bilayer graphene with and without a band gap. Two different conduction regimes are possible: (i) both sides of the junction have the same carrier type and (ii) one side of the junction is n-type while the other one is p-type. The first case shows Hall plateau-like features in the Hall resistance that fade away as the band gap opens. The second case exhibits a bend resistance that is asymmetric in magnetic field as a consequence of snake states along the pn-interface, where the maximum is shifted away from zero magnetic field.
-
graphene hall Bar with an asymmetric pn junction
Journal of Applied Physics, 2013Co-Authors: S P Milovanovic, Ramezani M Masir, F M PeetersAbstract:We investigated the magnetic field dependence of the Hall and the bend resistances in the ballistic regime for a single layer graphene Hall Bar Structure containing a pn-junction. When both regions are n-type the Hall resistance dominates and Hall type of plateaus are formed. These plateaus occur as a consequence of the restriction on the angle imposed by Snell's law allowing only electrons with a certain initial angles to transmit though the potential step. The size of the plateau and its position is determined by the position of the potential interface as well as the value of the applied potential. When the second region is p-type, the bend resistance dominates, which is asymmetric in field due to the presence of snake states. Changing the position of the pn-interface in the Hall Bar strongly affects these states and therefore the bend resistance is also changed. Changing the applied potential, we observe that the bend resistance exhibits a peak around the charge-neutrality point (CNP), which is independent of the position of the pn-interface, while the Hall resistance shows a sign reversal when the CNP is crossed, which is in very good agreement with a recent experiment [J. R. Williams and C. M. Marcus, Phys. Rev. Lett. 107, 046602 (2011)].
