Planar Structure Optimization of Extraordinary Magnetoresistance in Semiconductor–Metal Hybrids

Huang, Tiantian; Ye, Lingyun; Song, Kaichen; Deng, Fucheng

doi:10.1007/s10948-014-2537-9

Cited by 7 publications

(9 citation statements)

References 20 publications

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“…The asymmetric circular geometry (figure 2(b)) was based on our previous work [41] using α = 12/16 with a 90% offset in the metallic inclusion. The dimensions used in the bar-shape device (figure 2(c)) were also based on previous work [35,38] where it was shown that a length of 45 µm, a semiconductor width of 3 µm, a metal width of 15 µm and a voltage probe distance of 8 µm results in a maximal magnetoresistance at all magnetic fields. The multi-branched structure (figure 2(d)) was adapted from the work by Huang et al describing a Hall bar-like metal inclusion combined with ellipsoidal edges [38].…”

Section: Methodsmentioning

confidence: 99%

“…The dimensions used in the bar-shape device (figure 2(c)) were also based on previous work [35,38] where it was shown that a length of 45 µm, a semiconductor width of 3 µm, a metal width of 15 µm and a voltage probe distance of 8 µm results in a maximal magnetoresistance at all magnetic fields. The multi-branched structure (figure 2(d)) was adapted from the work by Huang et al describing a Hall bar-like metal inclusion combined with ellipsoidal edges [38]. The edges drastically reduce the zero-field resistance as the current trajectory is primarily going through the highly conducting metallic inclusion, yielding the highest simulated magnetoresistance of 10 10 % at 5 T reported to date.…”

Section: Methodsmentioning

confidence: 99%

“…Four of the key geometries explored for EMR are displayed in figure 2, which include the concentric circular devices, bar-shaped devices, the asymmetric off-center circular devices and more exotic multi-branched devices. As the EMR is a geometrical effect, reshaping the device geometry influences the magnetoresistive response dramatically [38][39][40]. The concentric circular and bar-shaped devices are the most commonly studied geometries and here a magnetoresistance up to 1.5 • 10 6 % for InSb and 1 • 10 7 % for encapsulated graphene have been shown experimentally at B = 5 T [8,30].…”

Section: Introductionmentioning

confidence: 93%

“…The material requirements sparked an interest in studying the behavior of EMR in various high-mobility materials, including InSb [8,[12][13][14][15][16][17], InAs [18][19][20], GaAs [21][22][23][24] and graphene [25][26][27][28][29][30]. Beyond investigating different material platforms and material parameters, there has also been a strong interest in exploring various EMR geometries [2,[31][32][33][34][35][36][37][38][39][40][41]. Four of the key geometries explored for EMR are displayed in figure 2, which include the concentric circular devices, bar-shaped devices, the asymmetric off-center circular devices and more exotic multi-branched devices.…”

Section: Introductionmentioning

confidence: 99%

“…The device symmetry is broken in the off-centered geometry, where simulations predict highly asymmetric magnetoresistance curves and a non-zero sensitivity (dR/dB > 0) towards weak magnetic fields [41]. Lastly, a few variants of branched structures, such as the one shown in figure 2(d), have also been investigated computationally, yielding a magnetoresistance of up to 10 10 % at 5 T [29,38].…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Universal material trends in extraordinary magnetoresistive devices

Erlandsen,

Désiré Pomar,

Kornblum

et al. 2023

J. Phys. Mater.

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Extraordinary magnetoresistance (EMR) is a geometric magnetoresistance emerging in hybrid systems typically comprising a high-mobility material and a metal. Due to a field-dependent redistribution of electrical currents in these devices, the electrical resistance at room temperature can increase by 10^7% when applying a magnetic field of 5 T. Although EMR holds considerable potential for realizing sensitive, all-electronic magnetometers, this potential is largely unmet. A key challenge is that the performance of EMR devices depends very sensitively on variations in a vast parameter space where changes in the device geometry and material properties produce widely different EMR performances. The challenge of navigating in the large parameter space is further amplified by the poor understanding of the interplay between the device geometry and material properties. By systematically varying the material parameters in four key EMR geometries using diffusive transport simulations, we here elucidate this interplay with the aim of finding universal guidelines for designing EMR devices. Common to all geometries, we find that the sensitivity scales inversely with the carrier density, while the MR reaches saturation at low carrier densities. Increasing the mobility beyond 20,000 cm^2/Vs is required to observe strong EMR effects at 1 T with the optimal magnetoresistance observed for mobilities between 100,000-500,000 cm^2/Vs. An interface resistance below 10^-4 Ohm*cm^2 between the constituent materials in the hybrid devices was also found to be a prerequisite for very high magnetoresistances in all geometries. By further simulating several high-mobility materials at room and cryogenic temperatures, we conclude that encapsulated graphene and InSb are amongst the most promising candidates for EMR devices showing high magnetoresistance exceeding 10^7% below 1 T at room temperature. This study paves the way for understanding how to realize EMR devices with record-high magnetoresistance and high sensitivity for detecting magnetic fields.

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