The historic de Haas van Alphen effect observed in the late 1950s in CSIR-NPL by J.S. Dhillon and D. Shoenberg in pure bismuth and zinc metal is revisited in this article hrough a single crystalline phase of bismuth crystal, which is observed in terms of resistivity as predicted by Shubnikov de Haas oscillations. The occurrence of oscillations in the transverse magnetic field confirms the presence of the Fermi surface. The single crystal of bismuth is grown through solid-state reaction under an optimized heat treatment whose purity and structural phase are confirmed through XRD, SEM, and EDAX.
We report on the Shubnikov de Haas (SdH) oscillations in the quasi two-dimensional molecular conductor $α-$(BETS)$_{2}$I$_{3}$ [BETS: bis(ethylenedithio)tetraselenafulvalene] laminated on polyimide films at 1.7 K. From the SdH phase factor, we verified experimentally that the material is in the Dirac fermion phase under pressure. $α-$(BETS)$_{2}$I$_{3}$ is in the vicinity of the phase transition between strongly correlated insulating and Dirac fermion phases, and is a possible candidate for an ambient-pressure molecular Dirac fermion system. However, the SdH oscillations indicate that the Berr…
Shubnikov-de Haas (SdH) oscillations, the most well-known magneto-oscillations caused by the quantization of electron energy levels in the presence of magnetic fields in two-dimensional (2D) electron systems, can be used to determine Fermi-surface properties and directly measure the Berry phase of the 2D systems. It is usually thought that transport measurements are required to measure the SdH oscillations. Contradicting this belief, we demonstrate that the SdH oscillations can be measured in graphene systems by carrying out scanning tunneling spectroscopy (STS) measurements. The energy-moment…
Anisotropic transport, Shubnikov-de Haas (SdH), and de Haas-van Alphen (dHvA) quantum oscillations studies are reported on a high-quality CoSi single crystal grown by the Czochralski method. Temperature-dependent resistivities indicate the dominating electron-electron scattering. Magnetoresistance (MR) at 2 K reaches 610% for I||[111] and B||[01-1], whereas it is 500% for I||[01-1] and B||[111]. A negative slope in field-dependent Hall resistivity suggests electrons are the majority carriers. The carrier concentration extracted from Hall conductivity indicates no electron-hole compensation. In…
We perform the quantum magnetotransport measurements and first-principles calculations on high quality single crystals of SmAlSi, a new topological Weyl semimetal candidate. At low temperatures, SmAlSi exhibits large non-saturated magnetoresistance (MR)~5200% (at 2 K, 48 T) and prominent Shubnikov-de Haas (SdH) oscillations, where MRs follow the power-law field dependence with exponent 1.52 at low fields (μ0H < 15 T) and linear behavior 1 under high fields (μ0H > 18 T). The analysis of angle dependent SdH oscillations reveal two fundamental frequencies originated from the Fermi surface (FS) po…
Bulk Fermi surface coexistence with Dirac surface state in Bi$_2$Se$_3$: a comparison of photoemission and Shubnikov-de Haas measurements
Shubnikov de Haas（SdH）振荡和角分辨光电子能谱（ARPES）被用来探测Bi 2Se 3单晶的费米面。我们发现，SdH和ARPES探针定量同意测量的有效质量和散装带色散。在高载流子密度的样品中，两个探针也同意在费米能级EF的确切位置，但对于较低的载流子密度的样品的差异出现在EF的位置。特别是，SdH揭示了载流子密度低至10^17cm-3的样品的体三维费米表面。我们提出了一个简单的机制来解释这些差异，并讨论了现有的和未来的拓扑绝缘体输运研究的后果。
Role of Se vacancies on Shubnikov de Haas oscillations in Bi2Se3: a combined magneto-resistance and positron annihilation study
磁电阻测量加上正电子寿命测量，以表征空位型缺陷，已进行了拓扑绝缘体（TI）系统Bi 2 Se 3，不同的Se/Bi的比例。在4 K至10 K温度范围内，在高达15 T的磁场中进行测量时，在标称Bi2Se3.1晶体中观察到明显的Shubnikov de Haas（SdH）振荡，磁场垂直于晶体的（001）平面。量子振荡，二维电子结构的特征，被认为只有在晶体中，具有较低浓度的硒空位，从正电子湮没光谱推断。
Investigating Shubnikov-de Haas (SdH) oscillations in high magnetic fields, we experimentally infer the electronic band structure of the quasi-two-dimensional electron gas (2DEG) at the ionic-liquid gated amorphous (a)-LaAlO$_3$/KTaO$_3$ interface. The angular dependence of SdH oscillations indicates a 2D confinement of a majority of electrons at the interface. However, additional SdH oscillations with an angle-independent frequency observed at high tilt angles indicate the coexistence of 3D charge carriers extending deep into the KTaO$_3$. The SdH oscillations measured in magnetic fields perp…
Shubnikov-de Haas oscillations of two-dimensional electron gases in AlYN/GaN and AlScN/GaN heterostructures
Cornell University（康奈尔大学）；Fraunhofer Institute for Applied Solid State Physics IAF（弗劳恩霍夫应用固态物理研究所）；Kavli Institute at Cornell for Nanoscale Science（康奈尔纳米科学卡弗里研究所）
Element semiconductor Te is very popular in both fundamental electronic structure study, and device fabrication research area due to its unique band structure. Specifically, in low temperatures, Te possesses strong quantum oscillations with magnetic field applied in basal plane, either following Shubnikov-de Haas (SdH) oscillation rule or following log-periodic oscillation rule. With magnetic field applied along the [001] direction, the SdH oscillations are attributed to the two-dimensional hole gas (2DHG) surface states. Here we reported an interesting SdH oscillation in Te-based single cryst…
Quantum Hall effect in multilayered massless Dirac fermion systems with tilted cones
报道了在多层无质量Dirac费米子系统$α$ -（BEDT-TTF）$_2$ I $_3$中首次观测到的Shubnikov-de Haas（SdH）振荡和量子化霍尔电阻.通过接触带电将空穴注入固定在聚萘二甲酸乙二醇酯（PEN）衬底上的薄晶体中。检测到SdH振荡的相位被Berry相位$π$修改，强烈表明在该系统中载流子掺杂是成功的。我们成功地用这种台阶探测到了二维狄拉克费米子系统的本质--量子霍尔效应。在该器件中，有效掺杂层的数量被检查为两个。我们发现，有效层之间的相关性在QHE中起着重要的作用。
We report a comprehensive magneto-transport study on single crystalline p-type topological crystalline insulator (TCI) SnTe, across the cubic-to-rhombohedral (R3m) transition which occurs as a function of temperature. The electrical resistivity of a well-characterized SnTe crystal shows evidence for the cubic-to-rhombohedral structural transition at T$_s$ $\sim$64,K and a carrier density of $\sim$1.8$\times$10$^{20}$ at 77,K. As a function of applied magnetic field perpendicular to the (100) plane, SnTe exhibits a large unsaturated linear magnetoresistance (LMR) reaching a value of 42% at 5K a…
We have performed magnetotransport measurements in CeTe$_{3}$ thin films down to $0.2~{\rm K}$. It is known that CeTe$_{3}$ has two magnetic transitions at $T_{\rm N1} \approx 3~{\rm K}$ and $T_{\rm N2} \approx 1~{\rm K}$. A clear Shubnikov-de-Haas (SdH) oscillation was observed at $4~{\rm K}$, demonstrating the strong two-dimensional nature in this material. Below $T_{\rm N2}$, the SdH oscillation has two frequencies, indicating that the Fermi surface could be slightly modulated due to the second magnetic transition. We also observed a magnetic hysteresis in the SdH oscillation below $T_{\rm …
Field driven Metal-Insulator transition in rhombohedral Bismuth and Arsenic crystals
CSIR-National Physical Laboratory（印度国家物理实验室）；Academy of Scientific and Innovative Research (AcSIR)（科学与创新研究学院）；Institute of Mathematical Sciences（数学科学研究所）
Quantum Oscillations in iron-doped topological insulator Sb2Te3 crystals
研究了Fe掺杂的拓扑绝缘体Sb 1. 96 Fe 0. 04 Te 3单晶的磁输运性质。与掺杂，能带结构的变化显着和多个费米口袋变得明显的舒布尼科夫-德哈斯振荡，在检测到的单一频率纯Sb 2 Te 3。使用互补密度泛函理论计算，我们确定了一个额外的体空穴袋引入的Γ点，其起源于与Fe掺杂剂相关的化学畸变。实验上，掺杂和未掺杂的样品都是空穴载流子占主导地位的，然而，Fe掺杂也降低了载流子密度和迁移率。分析了角度相关的量子振荡，以表征复杂的费米面和隔离的每个SdH功能的维数。在组件中，至少两个口袋根据它们的旋转依赖性具有2D样行为。这些结果表明杂化掺杂剂带与体和表面拓扑电子结构的复杂的相互作用。
We report large magnetoresistance (MR) and Shubnikov-de Haas (SdH) oscillations in single crystals of magnetically (M= Ni and Fe) doped M$_x$Bi$_{0.97-x}$Sb$_{0.03}$ ($x=$ 0, 0.02) topological insulators. The R$\bar{3}$m symmetry and phase have been confirmed by the Rietveld refinement of x-ray diffraction data. Interestingly, a magnetic field induced phase transition from semi-metallic to semi-conducting type is found with the energy gap around 80 meV at 15 Tesla in the $x=$ 0 sample. Moreover, we observe linear behavior of MR up to 15 Tesla in transverse mode and SdH oscillations in longitud…
