Electrical detection of spin-polarized current in topological insulator Bi1.5Sb0.5Te1.7Se1.3

Abstract

Spin-momentum locked (SML) topological surface state (TSS) provides exoticproperties for spintronics applications. The spin-polarized current, which emerges owing to the SML, can be directly detected by performing spin potentiometric measurement. We observed spin-polarized current using a bulk insulating topological insulator (TI), Bi 1.5 Sb 0.5 Te 1.7 Se 1.3 , and Co as the ferromagnetic spin probe. The spin voltage was probed with varying the bias current, temperature, and gate voltage.Moreover, we observed non-local spin-polarized current, which is regarded as a distinguishing property of TIs. The spin-polarization ratio of the non-local current was larger than that of the local current. These findings could reveal a more accurate approach to determine spin-polarization ratio at the TSS.Main Text:

Adjustable Quantum Interference Oscillations in Sb-Doped Bi2Se3 Topological Insulator Nanoribbons

“…Meanwhile, the ensemble-averaged FFT spectrum can be used to identify the electrical transport regime of the TI NRs at an arbitrary disorder strength. We expect the channel-length-dependent topological quantum interferometers of the TI NR to be useful for investigating various features of topological quantum devices combined with superconductivity, , ferromagnetism, , or nanomechanics …”

Photosensing and Characterizing of the Pristine and In-, Sn-Doped Bi2Se3 Nanoplatelets Fabricated by Thermal V–S Process

“…Owing to TIs' unique electronic properties, they have many potential applications, including photodetectors [14], lasers [15], gas sensors [16], spintronic devices [17], magnetoelectronic devices [18], quantum computers [19], and topological superconductors [20]. Several methods are commonly used to synthesize TIs; they include chemical vapor deposition [21], mechanical exfoliation [22], solvothermal synthesis [23], molecular beam epitaxy [24], atomic layer epitaxy [25], metal-organic chemical vapor deposition [26], pulsed laser deposition [27], magnetron sputtering [28], and the Bridgeman method [29].…”

Topological nature of higher-order hinge states revealed by spin transport

“…Upon changing the polarity of the bias current, the spin polarization of the nonlocal transport also experiences a reversal (Fig.4d, e), showing consistent spin-momentum locking with the local channel. To suppress the charge-current-spreading effect, the nearest nonlocal spin probe is set beyond 2 μm from the local electrode, where the distance is larger than the mean free path of electrons[54][55][56], facilitating the detection of spin diffusion process (Supplementary materials, Fig.S6). Figure4fshows the |∆𝑉 S | as a function of 𝐿, where 𝐿 is the distance between the nonlocal spin detector Co and the its nearest local Ti/Au electrode.…”