arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1506.04097cond-mat.mes-hall
收藏

无催化剂气相沉积Bi $_2$ Se $_3$晶体的相相干输运

Phase-coherent transport in catalyst-free vapor phase deposited Bi$_2$Se$_3$ crystals

R. Ockelmann, A. Müller, J. H. Hwang, S. Jafarpisheh, Drögeler, B. Beschoten, C. Stampfer

摘要:

使用无催化剂的气-固合成法生长可变厚度的自支撑Bi $_2$ Se $_3$单晶薄片,随后将其转移到干净的Si $^{++}$/SiO $_2$基底上,其中薄片以霍尔棒几何形状接触。低温磁电阻测量结果表明,在高磁场下,样品的磁电阻为线性,在低磁场下,样品的反局域化效应较弱。尽管整体较强的电荷载流子的可调性较薄的设备,我们发现,电子输运是占主导地位的所有设备的批量贡献。从WAL测量中提取的相位相干长度$ł_ϕ$随着电子密度的增加而线性增加,在1.7 K时超过$1 μ$ m。虽然$ł_ϕ$是在定性协议与电子-电子相互作用引起的退相,我们发现,自旋翻转散射过程限制$ł_ϕ$在低温下。

英文摘要:

Free-standing Bi$_2$Se$_3$ single crystal flakes of variable thickness are grown using a catalyst-free vapor-solid synthesis and are subsequently transferred onto a clean Si$^{++}$/SiO$_2$ substrate where the flakes are contacted in Hall bar geometry. Low temperature magneto-resistance measurements are presented which show a linear magneto-resistance for high magnetic fields and weak anti-localization (WAL) at low fields. Despite an overall strong charge carrier tunability for thinner devices, we find that electron transport is dominated by bulk contributions for all devices. Phase coherence lengths $ł_ϕ$ as extracted from WAL measurements increase linearly with increasing electron density exceeding $1 μ$m at 1.7 K. While $ł_ϕ$ is in qualitative agreement with electron electron interaction-induced dephasing, we find that spin flip scattering processes limit $ł_ϕ$ at low temperatures.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑