Low-frequency flicker noise is usually associated with material defects or imperfection of fabrication procedure. Up to now, there is only very limited knowledge about flicker noise of the topological insulator, whose...Low-frequency flicker noise is usually associated with material defects or imperfection of fabrication procedure. Up to now, there is only very limited knowledge about flicker noise of the topological insulator, whose topologically protected conducting surface is theoretically immune to back scattering. To suppress the bulk conductivity we synthesize antimony doped Bi2Se3 nanowires and conduct transport measurements at cryogenic temperatures. The low-frequency current noise measurement shows that the noise amplitude at the high-drain current regime can be described by Hooge＇s empirical relationship, while the noise level is significantly lower than that predicted by Hooge＇s model near the Dirac point. Furthermore, different frequency responses of noise power spectrum density for specific drain currents at the low drain current regime indicate the complex origin of noise sources of topological insulator.展开更多
Bi2Se3, as a three-dimensional topological insulator, has attracted worldwide attention for its unique surface states which are protected by time-reversal symmetry. Here we report the synthesis and characterization of...Bi2Se3, as a three-dimensional topological insulator, has attracted worldwide attention for its unique surface states which are protected by time-reversal symmetry. Here we report the synthesis and characterization of high-quality singlecrystalline Bi2Se3 nanowires. Bi2Se3 nanowires were synthesized by chemical vapor deposition（CVD） method via goldcatalyzed vapor-liquid-solid（VLS） mechanism. The structure and morphology were characterized by scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, x-ray photoelectron spectroscopy（XPS）, and Raman spectroscopy. In magnetotransport measurements, the Aharonov–Bohm（AB） effect was observed in a nanowire-based nanodevice, suggesting the existence of surface states in Bi2Se3 nanowires.展开更多
基金Supported by the National Basic Research Program of China under Grant No 2012CB921703the National Natural Science Foundation of China under Grant Nos 11174357 and 11574379the Strategic Priority Research Program of Chinese Academy of Sciences under Grant No XDB07010300
文摘Low-frequency flicker noise is usually associated with material defects or imperfection of fabrication procedure. Up to now, there is only very limited knowledge about flicker noise of the topological insulator, whose topologically protected conducting surface is theoretically immune to back scattering. To suppress the bulk conductivity we synthesize antimony doped Bi2Se3 nanowires and conduct transport measurements at cryogenic temperatures. The low-frequency current noise measurement shows that the noise amplitude at the high-drain current regime can be described by Hooge＇s empirical relationship, while the noise level is significantly lower than that predicted by Hooge＇s model near the Dirac point. Furthermore, different frequency responses of noise power spectrum density for specific drain currents at the low drain current regime indicate the complex origin of noise sources of topological insulator.
基金Project supported by the National Key Basic Research Program of China(Grant Nos.2014CB921103 and 2013CB921103)the National Natural Science Foundation of China(Grant Nos.11274003 and 91421109)Collaborative Innovation Center of Solid-State Lighting and Energy-Saving Electronics,China
文摘Bi2Se3, as a three-dimensional topological insulator, has attracted worldwide attention for its unique surface states which are protected by time-reversal symmetry. Here we report the synthesis and characterization of high-quality singlecrystalline Bi2Se3 nanowires. Bi2Se3 nanowires were synthesized by chemical vapor deposition（CVD） method via goldcatalyzed vapor-liquid-solid（VLS） mechanism. The structure and morphology were characterized by scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, x-ray photoelectron spectroscopy（XPS）, and Raman spectroscopy. In magnetotransport measurements, the Aharonov–Bohm（AB） effect was observed in a nanowire-based nanodevice, suggesting the existence of surface states in Bi2Se3 nanowires.
