Magnetotransport and de Haas-van Alphen measurements in the type-II Weyl semimetal TaIrTe$_4$
Seunghyun Khim, Klaus Koepernik, Dmitry V. Efremov, J. Klotz, T. Förster, J. Wosnitza, Mihai I. Sturza, Sabine Wurmehl, Christian Hess, Jeroen van den Brink, Bernd Büchner
The layered ternary compound TaIrTe$_4$ has been predicted to be a type-II Weyl semimetal with only four Weyl points just above the Fermi energy. Performing magnetotransport measurements on this material we find that the resistivity does not saturate for fields up to 70 T and follows a $ ρ\sim B^{1.5}$ dependence. Angular-dependent de Haas-van Alphen (dHvA) measurements reveal four distinct frequencies. Analyzing these magnetic quantum oscillations by use of density functional theory (DFT) calculations we establish that in TaIrTe$_4$ the Weyl points are located merely $\sim$ 40-50 meV above the chemical potential, suggesting that the chemical potential can be tuned into the four Weyl nodes by moderate chemistry or external pressure, maximizing their chiral effects on electronic and magnetotransport properties.
We have observed Shubnikov-de Haas and de Haas-van Alphen effect in the single crystals of three dimensional Dirac semimetal Cd$_{3}$As$_{2}$ upto 50 K, traceable at field as low as 2 T and 1 T, respectively. The values of Fermi wave vector, Fermi velocity, and effective cyclotron mass of charge carrier, calculated from both the techniques, are close to each other and match well with the earlier reports. However, the de Haas-van Alphen effect clearly reflects the existence of two different Fermi surface cross-sections along certain direction and a non-trivial Berry's phase which is the signatu…
de Haas-van Alphen oscillation spectrum of two-dimensional systems is studied for general power law energy dispersion, yielding a Fermi surface area of the form $S(E)\propto E^α$ for a given energy $E$. The case $α=1$ stands for the parabolic energy dispersion. It is demonstrated that the periodicity of the magnetic oscillations in inverse field can depend notably on the temperature. We evaluated analytically the Fourier spectrum of these oscillations to evidence the frequency shift and smearing of the main peak structure as the temperature increases.
Field-, temperature- and angle-dependent Fourier amplitude of de Haas-van Alphen (dHvA) oscillations are calculated for compensated two-dimensional (2D) metals with textbook Fermi surface (FS) composed of one hole and two electron orbits connected by magnetic breakdown. It is demonstrated that, taking into account the opposite sign of electron and hole orbits, a given Fourier component involves combination of several orbits, the contribution of which must be included in the calculations. Such FS is observed in the strongly 2D organic metal alpha-'pseudo-kappa'-(ET)4H3O[Fe(C2O4)3].(C6H4Br2), dH…
De Haas-van Alphen oscillations of the organic metal \k{appa}-(ET) 2 Cu(SCN) 2 have been measured up to 55 T at liquid helium temperatures. The Fermi surface of this charge transfer salt is a textbook example of linear chain of orbits coupled by magnetic breakdown. Accordingly, the oscillation spectrum is composed of linear combinations of the frequencies linked to the $α$ and magnetic breakdown-induced $β$ orbits. The field and temperature dependence of all the observed Fourier components, in particular the "forbidden frequency" $β$ -- $α$ which cannot correspond to a classical orbit, are qua…
The de Haas-van Alphen effect (dHvAe), describing oscillations of the magnetization as a function of magnetic field, is commonly assumed to be a definite sign for the presence of a Fermi surface (FS). Indeed, the effect forms the basis of a well-established experimental procedure for accurately measuring FS topology and geometry of metallic systems, with parameters commonly extracted by fitting to the Lifshitz-Kosevich (LK) theory based on Fermi liquid theory. Here we show that, in contrast to this canonical situation, there can be quantum oscillations even for band insulators of certain types…
The superconducting pyrochlore oxide Cd2Re2O7 shows a structural transition with inversion symmetry breaking (ISB) at Ts1 = 200 K. A recent theory [L. Fu, Phys. Rev. Lett. 115, 026401 (2015)] suggests that the origin is an electronic instability that leads to a multipolar order in the spin-orbit-coupled metal. To observe the Fermi surface of the low-temperature phase of Cd2Re2O7, we perform de Haas-van Alphen effect measurements by means of magnetic torque. In reference to a calculated band structure, the spin-split Fermi surfaces with large cyclotron masses of 5-9m0 are revealed. The splittin…
We report on the results of a de Haas-van Alphen (dHvA) measurement performed on the recently discovered antiferromagnet URhIn$_5$ ($T_N$ = 98 K), a 5\textit{f}-analogue of the well studied heavy fermion antiferromagnet CeRhIn$_5$. The Fermi surface is found to consist of four surfaces: a roughly spherical pocket $β$, with $F_β\simeq 0.3$ kT; a pillow-shaped closed surface, $α$, with $F_α\simeq 1.1$ kT; and two higher frequencies $γ_1$ with $F_{γ_1} \simeq 3.2$ kT and $γ_2$ with $F_{γ_2} \simeq 3.5$ kT that are seen only near the \textit{c}-axis, and that may arise on cylindrical Fermi surface…
Cyclotron mass-selective de Haas-van Alphen measurements using temperature modulation
School of Natural Sciences, Technical University of Munich（自然科学学院，慕尼黑工业大学）；Zentrum für QuantumEngineering (ZQE), Technical University of Munich（量子工程中心（ZQE），慕尼黑工业大学）；Fakultät für Physik, Ludwig-Maximilians-Universität（物理学院，路德维希-马克西米利安大学）；Heinz Maier-Leibnitz Zentrum (MLZ), Technical University of Munich（海因茨·迈尔-莱布尼茨中心（MLZ），慕尼黑工业大学）；Munich Center for Quantum Science and Technology (MCQST), Technical University of Munich（慕尼黑量子科学与技术中心（MCQST），慕尼黑工业大学）
提出一种温度调制的 de Haas-van Alphen 测量技术，通过非单调振幅演化选择性探测不同有效质量的量子振荡，并实验验证其在 MoSi2 中分离重轨道弱信号的能力。
Because of the unique physical properties and potential applications, the exploration of quantum materials with diverse symmetry-protected topological states has attracted considerable interest in the condensed-matter community in recent years. Most of the topologically nontirvial materials identified thus far have two-dimensional or three-dimensional structural characteristics, while the quasi-one-dimensional (quasi-1D) analogs are rare. Here we report on anisotropic magnetoresistance, Hall effect, and quantum de Haas$-$van Alphen (dHvA) oscillations in TaPtTe$_5$ single crystals, which posse…
Superconducting Fluctuations and the Reduced Dimensionality of the Organic Superconductor $κ$- (BEDT-TTF)$_{2}$Cu(NCS)$_{2}$ as Observed through Measurements of the de Haas-van Alphen Effect
de Haas-van Alphen oscillations in the underdoped cuprate YBa$_2$Cu$_3$O$_{6.5}$
利用转矩技术在高达59 T的脉冲磁场中观察到欠掺杂铜氧化物YBa $_2$ Cu $_3$ O $_{6.5}$的de Haas van Alphen效应。在$\sim$ 30 T的不可逆性场以上，磁化强度表现出明显的量子振荡，单频为540 T，回旋质量为自由电子质量的1.76倍，与先前观察到的Shubnikov-de Haas振荡非常一致。振荡遵循费米液体理论的标准Lifshitz-Kosevich公式。这种量子振荡的热力学观测证实了在铜酸盐的赝能隙相中存在一个定义明确、紧密且相干的费米面。
We present a de Haas-van Alphen study of the Fermi surface of the low temperature antiferromagnet CeZn11 and its non-magnetic analogue LaZn11, measured by torque magnetometry up to fields of 33T and at temperatures down to 320 mK. Both systems possess similar de Haas-van Alphen frequencies, with three clear sets of features - ranging from 50T to 4kT - corresponding to three bands of a complex Fermi surface, with an expected fourth band also seen weakly in CeZn11. The effective masses of the charge carriers are very light (<1 me) in LaZn11 but a factor of 2 - 4 larger in CeZn11, indicative of s…
Multiple Quantum Oscillations in the de Haas van Alphen Spectra of the Underdoped High Temperature Superconductor YBa_2Cu_3O_6.5
通过改进实验条件和大量的数据积累，我们对欠掺杂高温超导体$_{2}$ O $_{3}$的de Haas-van Alphen效应的测量取得了很高的精度。我们发现，主振荡，到目前为止被认为是单频，是由三个紧密间隔的频率。我们把这归因于双层分裂和一个单一的准二维费米面的翘曲，表明\emph{c}轴的相干性恢复在低温下在欠掺杂的铜氧化物。我们的结果不支持最近报道的在同一化合物中存在1650 T量级的更大频率[S. E. Sebastian { \it等人}，Nature { \bf 454}，200（2008）]。
The de Haas-van Alphen effect (dHvAe) describes the periodic oscillation of the magnetisation in a material as a function of inverse applied magnetic field. It forms the basis of a well established procedure for measuring Fermi surface properties and its observation is typically taken as a direct signature of a system being metallic. However, certain insulators can show similar oscillations of the magnetisation from quantisation of the energies of electron states in filled bands. Recently the theory of such an ${\it anomalous}$ dHvAe (AdHvAe) has been worked out but so far there is no clear ex…
The de Haas van Alphen effect near a quantum critical end point in Sr_3Ru_2O_7
高度相关的电子材料是一种可以出现许多新的物质状态的系统。在复杂材料中，有利于形成电子液体奇异相的一种特殊情况是，在相图中存在量子临界点（QCP）。参数空间中的邻近区域揭示了不寻常的物理性质，称为非费米液体行为。量子临界研究中的一个重要问题是研究材料的费米面在QCP附近的演化。研究材料的FS的传统方法是de Haas van Alphen效应（dHvA）。量子临界终点（QCEP）已被报道在高度相关的金属Sr3Ru2O7，这是调谐使用磁场高到足以执行dHvA实验。此外，它还具有一个新的紧急阶段附近的QCEP，一种电子排序的ESTA类型。本论文的主要工作是利用dHvA效应研究Sr_3Ru_2O_7的荧光光谱。探讨了三个方面。第一个是在QCEP出现的区域之上和之下确定FS。第二个是寻找量子振荡内的相位。第三个是重新调查行为的准粒子有效质量附近的FS。一个完整的鲁棒模型的FS的Sr3Ru2O7在零场被确定。此外，准粒子质量的新测量显示，QCEP周围任何地方都不存在质量增强。最后，我们报告的dHvA振荡内的相位，这表明，载体由朗道准粒子。
Layered three-dimensional (3D) topological semimetals have attracted intensively attention due to the exotic phenomena and abundantly tunable properties. Here we report the experimental evidence for the 3D topological semimetal phase in layered material TaNiTe5 single crystals through quantum oscillations. Strong quantum oscillations have been observed with diamagnetism background in TaNiTe5. By analyzing the de Haas-van Alphen oscillations, multi-periodic oscillations were extracted, in content with magnetotransport measurements. Moreover, nontrivial "π" Berry phase with 3D Fermi surface is i…
Comment on Multiple Quantum Oscillations in the de Haas - van Alphen Spectra of the Underdoped High-Temperature Superconductor YBa2Cu3O6.5 (A. Audouard et al., Phys. Rev. Lett. 103 (2009) 157003)
A de Haas-van Alphen study of the filled skutterudite compounds PrOs$_4$As$_{12}$ and LaOs$_4$As$_{12}$
在高达40 T的磁场下，对填充方钴矿PrOs $_4$ As $_{12}$和LaOs $_4$ As $_{12}$单晶的磁化率和de Haas-van Alphen效应随磁场方向的变化进行了全面的研究。几个峰值中观察到的低场磁化率的PrOs $_4$作为$_{12}$，对应于级联的变磁性转变分离的低场反铁磁和高场顺磁金属（PMM）相。de Haas-van Alphen实验表明，PMM相的PrOs $_4$ As $_{12}$和LaOs $_4$ As $_{12}$的费米面拓扑结构非常相似.此外，它们与LaOs $_4$ As $_{12}$在PrOs $_4$ As $_{12}$晶格上的能带结构计算的预测也有合理的一致性.这两个观察结果表明，Pr 4 $f$电子的PMM阶段的巡回准粒子的数量贡献不大。然而，虽然LaOs $_4$ As $_{12}$的性质表明一个传统的超导费米液体，直接交换和电子相关的影响被检测到的PMM相的PrOs $_4$ As $_{12}$。例如，准粒子的有效质量在PrOs $_4$作为$_{12}$被发现减少与增加的领域，可能反映了逐渐抑制与接近的低温，低场反铁磁状态的磁波动。
We have performed de Haas-van Alphen (dHvA) measurements of the heavy-fermion superconductor CeCoIn$_5$ down to 2 mK above the upper critical field. We find that the dHvA amplitudes show an anomalous suppression, concomitantly with a shift of the dHvA frequency, below the transition temperature $T_{\rm n}=20$ mK. We suggest that the change is owing to magnetic breakdown caused by a field-induced antiferromagnetic (AFM) state emerging below $T_{\rm n}$, revealing the origin of the field-induced quantum critical point (QCP) in CeCoIn$_5$. The field dependence of $T_{\rm n}$ is found to be very w…
Fermiology of the kagome compound LuNb6Sn6 probed by de Haas-van Alphen oscillations
National High Magnetic Field Laboratory, Los Alamos National Laboratory（洛斯阿拉莫斯国家实验室国家高磁场实验室）；Materials Science and Technology Division, Oak Ridge National Laboratory（橡树岭国家实验室材料科学与技术分部）
Fermi surface in KFe2As2 determined via de Haas-van Alphen oscillation measurements
我们用de Haas-van Alphen（dHvA）方法完全确定了KFe $_2$ As $_2$的费米面。在KFe $_2$ As $_2$中观察到基频$ε$、$α$、$ζ$和$β$。第一个是由于孔柱附近的布里渊区的X点，而其他的孔柱在$Γ$点。我们还观察到$α$和$ζ$之间的磁击穿频率，并提出了一个合理的解释。实验频率显示偏离带结构计算预测的频率。已经发现$B \parallel c$的有效质量高达19 $m_e$，$m_e$是自由电子质量。计算得到的载流子数和索末菲系数分别为1.01 - 1.03个空穴/分子式单元和82 - 94 mJmol $^{-1}$ K $^{-2}$，与化学计量和直接测量值93 mJmol $^{-1}$ K $^{-2}$一致[H.泽\textit{et al} .，日本物理学会\textbf{80SA}，SA 118（2011）]。索末菲系数在带值上增强了约9倍，表明低能自旋和/或轨道波动的重要性，并将KFe $_2$ As $_2$置于强相关金属中。我们还对Ba $_{0.07}$ K $_{0.93}$ Fe $_2$ As $_2$进行了dHvA测量，并观察了$α$和$β$频率。
We report the first observation of the de Haas-van Alphen (dHvA) effect in the novel spin-triplet superconductor UTe2 using high quality single crystals with the high residual resistivity ratio (RRR) over 200. The dHvA frequencies, named alpha and beta, are detected for the field directions between c and a-axes. The frequency of branch beta increases rapidly with the field angle tilted from c to a-axis, while branch alpha splits, owing to the maximal and minimal cross-sectional areas from the same Fermi surface. Both dHvA branches, alpha and beta reveal two kinds of cylindrical Fermi surfaces …
