scholarly journals Tunable Berry curvature and transport crossover in topological Dirac semimetal KZnBi

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Junseong Song ◽  
Byung Cheol Park ◽  
Kyung Ik Sim ◽  
Joonho Bang ◽  
Sunghun Kim ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Hall Resistance ◽  
Rotational Axis ◽  
Material System ◽  
Chiral Fermion ◽  
Quantum Phases ◽  
Berry Curvature ◽  
Dirac Semimetal ◽  
Dirac Semimetals ◽  
Single Material

AbstractTopological Dirac semimetals have emerged as a platform to engineer Berry curvature with time-reversal symmetry breaking, which allows to access diverse quantum states in a single material system. It is of interest to realize such diversity in Dirac semimetals that provides insight on correlation between Berry curvature and quantum transport phenomena. Here, we report the transition between anomalous Hall and chiral fermion states in three-dimensional topological Dirac semimetal KZnBi, which is demonstrated by tuning the direction and flux of Berry curvature. Angle-dependent magneto-transport measurements show that both anomalous Hall resistance and positive magnetoresistance are maximized at 0° between net Berry curvature and rotational axis. We find that the unexpected crossover of anomalous Hall resistance and negative magnetoresistance suddenly occurs when the angle reaches to ~70°, indicating that Berry curvature strongly correlates with quantum transports of Dirac and chiral fermions. It would be interesting to tune Berry curvature within other quantum phases such as topological superconductivity.

scholarly journals Orbit topology analyzed from π phase shift of magnetic quantum oscillations in three-dimensional Dirac semimetal

2021 ◽  
Vol 118 (29) ◽  
pp. e2023027118
Author(s):  
Sang-Eon Lee ◽  
Myeong-jun Oh ◽  
Sanghyun Ji ◽  
Jinsu Kim ◽  
Jin-Hyeon Jun ◽  
...  
Keyword(s):  
Phase Shift ◽  
Three Dimensional ◽  
Dirac Fermion ◽  
Quantum Oscillations ◽  
Dirac Semimetal ◽  
Single Orbit ◽  
Dirac Materials ◽  
Dirac Semimetals ◽  
Cyclotron Mass ◽  
Magnetic Quantum Oscillations

With the emergence of Dirac fermion physics in the field of condensed matter, magnetic quantum oscillations (MQOs) have been used to discern the topology of orbits in Dirac materials. However, many previous researchers have relied on the single-orbit Lifshitz–Kosevich (LK) formula, which overlooks the significant effect of degenerate orbits on MQOs. Since the single-orbit LK formula is valid for massless Dirac semimetals with small cyclotron masses, it is imperative to generalize the method applicable to a wide range of Dirac semimetals, whether massless or massive. This report demonstrates how spin-degenerate orbits affect the phases in MQOs of three-dimensional massive Dirac semimetal, NbSb2. With varying the direction of the magnetic field, an abrupt π phase shift is observed due to the interference between the spin-degenerate orbits. We investigate the effect of cyclotron mass on the π phase shift and verify its close relation to the phase from the Zeeman coupling. We find that the π phase shift occurs when the cyclotron mass is half of the electron mass, indicating the effective spin gyromagnetic ratio as gs = 2. Our approach is not only useful for analyzing MQOs of massless Dirac semimetals with a small cyclotron mass but also can be used for MQOs in massive Dirac materials with degenerate orbits, especially in topological materials with a sufficiently large cyclotron mass. Furthermore, this method provides a useful way to estimate the precise gs value of the material.

scholarly journals Berry paramagnetism in the Dirac semimetal ZrTe5

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Sanghyun Ji ◽  
Sang-Eon Lee ◽  
Myung-Hwa Jung
Keyword(s):  
Electrical Transport ◽  
Berry Phase ◽  
Three Dimensional ◽  
Peak Position ◽  
Quantum Oscillation ◽  
Band Shift ◽  
Dirac Semimetal ◽  
Linear Band ◽  
Dirac Semimetals ◽  
Unique Band

AbstractDirac matters have attracted a lot of interest due to their unique band structure with linear band dispersions, which have great potential for technological applications. Recently, three-dimensional Dirac and Weyl semimetals have invoked distinctive phenomena originating from a non-trivial Berry phase. In this study, we prepare single crystals of TixZr1-xTe5 with a highly anisotropic Fermi surface. Our detailed electrical transport measurements reveal that the crystals show the Lifshitz transition, and Ti doping induces a band shift. Further quantum oscillation analyses demonstrate that the TixZr1-xTe5 crystals are 3D Dirac semimetals. Additionally, we observed a minimum temperature-dependent magnetic susceptibility, which is close to a peak position of electrical resistivity. This observation is interpreted in terms of the Berry paramagnetism. Our finding paves the way to determine a band topology by magnetism and also provides a platform to apply the Berry magnetism to Dirac semimetals.

scholarly journals Half-Dirac Semimetal and Quantum Anomalous Hall Effect in Kagome Cd2N3 Lattice

2020 ◽  
Author(s):  
Xinyang Li ◽  
Weixiao Ji ◽  
Peiji Wang ◽  
Chang-wen Zhang
Keyword(s):  
Hall Effect ◽  
Quantum State ◽  
Anomalous Hall Effect ◽  
Topological Phases ◽  
Dirac Semimetal ◽  
Quantum Anomalous Hall Effect ◽  
Dirac Materials ◽  
Low Dimensionality ◽  
Dirac Semimetals ◽  
Topological Phases Of Matter

Half-Dirac semimetals (HDSs), which possess 100% spin-polarizations for Dirac materials, are highly desirable for exploring various topological phases of matter, as low-dimensionality opens unprecedented opportunities for manipulating the quantum state...

Thickness-Controlled Three-Dimensional Dirac Semimetal for Scalable High-Performance Terahertz Optoelectronics

ACS Photonics ◽  
2021 ◽  
Author(s):  
Xiaomei Yao ◽  
Shengxi Zhang ◽  
Qiang Sun ◽  
Peizong Chen ◽  
Xutao Zhang ◽  
...  
Keyword(s):  
High Performance ◽  
Three Dimensional ◽  
Dirac Semimetal

scholarly journals Evidence of Topological Surface State in Three-Dimensional Dirac Semimetal Cd3As2

2014 ◽  
Vol 4 (1) ◽  
Author(s):  
Hemian Yi ◽  
Zhijun Wang ◽  
Chaoyu Chen ◽  
Youguo Shi ◽  
Ya Feng ◽  
...  
Keyword(s):  
Surface State ◽  
Three Dimensional ◽  
Dirac Semimetal ◽  
Topological Surface ◽  
Topological Surface State

Tunable coherent perfect absorption in three-dimensional Dirac semimetal films

2021 ◽  
Vol 19 (8) ◽  
pp. 081601
Author(s):  
Jipeng Wu ◽  
Jie Tang ◽  
Rongzhou Zeng ◽  
Xiaoyu Dai ◽  
Yuanjiang Xiang
Keyword(s):  
Three Dimensional ◽  
Perfect Absorption ◽  
Dirac Semimetal ◽  
Coherent Perfect Absorption

High Cycle Fatigue Resistance and Reliability Assessment of Flexible Printed Circuitry

2002 ◽  
Vol 124 (3) ◽  
pp. 254-259 ◽  
Author(s):  
Elena Martynenko ◽  
Wen Zhou ◽  
Alexander Chudnovsky ◽  
Ron S. Li ◽  
Larry Poglitsch
Keyword(s):  
Fatigue Resistance ◽  
High Cycle Fatigue ◽  
Failure Mechanisms ◽  
Three Dimensional ◽  
Reliability Assessment ◽  
Core Layer ◽  
High Strength ◽  
Multiple Cracks ◽  
Material System ◽  
Cycle Fatigue

Flexible printed circuitry (FPC) is a patterned array of conductors supported by a flexible dielectric film made of high strength polymer material such as polyimide. The flexibility of FPC provides an opportunity for three dimensional packaging, easy interconnections and dynamic applications. The polymeric core layer is the primary load bearing structure when the substrate is not supported by a rigid plate. In its composite structure, the conductive layers are more vulnerable to failure due to their lower flexibility compared to the core layer. Fatigue data on FPCs are not commonly available in published literature. Presented in this paper is the fatigue resistance and reliability assessment of polyimide based FPCs. Fatigue resistance of a specific material system was analyzed as a function of temperature and frequency through experiments that utilized a specially designed experimental setup consisting of sine servo controller, electrodynamic shaker, continuity monitor and temperature chamber. The fatigue characteristics of the selected material system are summarized in the form of S-N diagrams. Significant decrease in fatigue lifetime has been observed due to higher displacements in high cycle fatigue. Observed temperature effect was however counter-intuitive. Failure mechanisms are discussed and complete fracture analysis is presented. In various FPC systems, it has been found that the changes take place in FPC failure mechanisms from well-developed and aligned single cracks through the width at low temperature to an array of multiple cracks with random sizes and locations at high temperature.

Transferred-Substrate InGaAsP-Based Thermionic Emission Coolers

2000 ◽  
Author(s):  
Christopher J. LaBounty ◽  
Gerry Robinson ◽  
Patrick Abraham ◽  
Ali Shakouri ◽  
John E. Bowers
Keyword(s):  
Thermal Resistance ◽  
Three Dimensional ◽  
Thermionic Emission ◽  
Copper Film ◽  
Cooling Power ◽  
Material System ◽  
Inp Substrate ◽  
Order Of Magnitude ◽  
Thin Copper Film ◽  
Thermally Conducting

Abstract Most optoelectronic devices are based on III-V semiconductors such as the InP/InGaAsP material system. Solid state refrigerators based on the same material system can be monolithically integrated with optoelectronics. Thermionic emission cooling in InGaAsP-based heterostructures has been shown experimentally to provide cooling power densities of several 100 W/cm2. Cooling by several degrees across thin films on the order of a micron thick has been demonstrated. Thermionic emission of hot electrons over heterobarriers allows for enhanced cooling power beyond what is possible from the bulk thermoelectric properties. The thermal resistance of the InP substrate between the hot side of the thin film cooler and the heat sink is found to be a limitation in cooler performance. Several possibilities are examined for replacing the InP substrate with a higher thermally conducting one such as silicon, copper, or even diamond, and a process for substrate transfer to a thin copper film has been developed. Three-dimensional simulations predict an order of magnitude improvement in the thermal resistance of the substrate. Experimental results of packaged InGaAsP coolers with copper substrates will be discussed.

Sign in / Sign up

Export Citation Format

Share Document