A5002633473- Physics of Superconductivity and Magnetism
- Topological Materials and Phenomena
- 2D Materials and Applications
- Advanced Condensed Matter Physics
- Quantum and electron transport phenomena
- Electronic and Structural Properties of Oxides
- Magnetic and transport properties of perovskites and related materials
- Organic and Molecular Conductors Research
- Perovskite Materials and Applications
- Advanced Chemical Physics Studies
- Terahertz technology and applications
- Iron-based superconductors research
- Cold Atom Physics and Bose-Einstein Condensates
- Semiconductor Quantum Structures and Devices
- Quantum, superfluid, helium dynamics
- Magnetic properties of thin films
- Graphene research and applications
- Photoreceptor and optogenetics research
- Inorganic Chemistry and Materials
- Solid-state spectroscopy and crystallography
- Advanced Thermoelectric Materials and Devices
- Neuroscience and Neural Engineering
- Photonic and Optical Devices
- Rare-earth and actinide compounds
- Spectroscopy and Quantum Chemical Studies
Peking University
2015-2024
Chongqing University
2007-2024
Engineering and Physical Sciences Research Council
2017-2018
University of Sheffield
2017-2018
Three dimensional (3D) topological Dirac materials are under intensive study recently. The layered compound ZrTe$_5$ has been suggested to be one of them by transport and ARPES experiments. Here, we perform infrared reflectivity measurement investigate the underlying physics this material. derived optical conductivity exhibits linear increasing with frequency below normal interband transitions, which provides first spectroscopic proof a 3D semimetal. Apart from that, plasma edge shifts...
In condensed matter physics, materials with kagome lattice display a range of exotic quantum states, including charge density wave (CDW), superconductivity, and magnetism. Recently, the intermetallic metal ${\mathrm{ScV}}_{6}{\mathrm{Sn}}_{6}$ was discovered to undergo first-order structural phase transition formation $\sqrt{3}\ifmmode\times\else\texttimes\fi{}\sqrt{3}\ifmmode\times\else\texttimes\fi{}3$ CDW at around 92 K. The bulk electronic band properties are crucial understanding origin...
Recently, kagome lattice metal AV$_3$Sb$_5$ (A = K, Rb, Cs) family has received wide attention due to its presence of superconductivity, charge density wave (CDW) and peculiar properties from topological nontrivial electronic structure. With time-resolved pump-probe spectroscopy, we show that the excited quasiparticle relaxation dynamics can be explained by formation energy gap below phase transition being similar a usual second-order CDW condensate, contrast, structure change is...
Charge density wave (CDW) is one of the most fundamental quantum phenomena in solids. Different from ordinary metals which only single-particle excitations exist, CDW also has collective and can carry electric current a fashion. Manipulating this condensation for applications long been goal condensed matter materials community. We show that system 1T-TaS2 highly sensitive to light directly visible down terahertz, with responsivities on order ~1 AW-1 at room temperature. Our findings open new...
Ultrafast control of material physical properties represents a rapidly developing field in condensed matter physics. Yet, accessing the long-lived photoinduced electronic states is still its early stages, especially with respect to an insulator metal phase transition. Here, by combining transport measurement ultrashort photoexcitation and coherent phonon spectroscopy, we report on multistage transitions Ta2NiSe5. Upon excitation weak pulse intensity, system triggered short-lived state...
Recent development of ultrashort laser pulses allows for optical control structural and electronic properties complex quantum materials. The layered transition metal dichalcogenide MoTe2, which can crystalize into several different structures with distinct topological properties, provides possibilities to or switch between phases. In this study we report a photo-induced sub-picosecond the type-II Weyl semimetal phase normal in bulk crystalline MoTe2 by using ultrafast pump-probe...
Searching for Kitaev quantum spin liquids (QSLs) is a fascinating and challenging problem. Much effort has been devoted to honeycomb lattice candidates with strong spin-orbit coupling in $5d$-electron iridates $4d$-electron ${\mathrm{RuCl}}_{3}$. Recently, theoretical studies suggested that $3{d}^{7}$ Co-based materials high state $S=3/2$ effective orbital angular momentum $L=1$ could also be promising of QSL. One the candidates, ${\mathrm{BaCo}}_{2}{({\mathrm{AsO}}_{4})}_{2}$, was revisited...
CuTe is a two-dimensional (2D) layered material; yet it forms quasi-one-dimensional (quasi-1D) charge-density-wave (CDW) along the $a$ axis in $ab$ plane at high transition temperature ${T}_{\mathrm{CDW}}=335\phantom{\rule{0.16em}{0ex}}\mathrm{K}$. However, anisotropic properties of remain to be explored. Here, we performed combined transport, polarized infrared reflectivity, and ultrafast pump-probe spectroscopy studies investigate underlying CDW physics CuTe. Polarized optical measurements...
Using infrared spectroscopy and ultrafast pump probe measurement, we have studied the two charge-density-wave (CDW) instabilities in layered compound LaAgSb_{2}. The development of CDW energy gaps was clearly observed by optical spectroscopy, which removed most free carrier spectral weight. More interestingly, our time-resolved measurements revealed coherent oscillations that softened approaching phase transition temperatures, respectively. We addressed these come from amplitude modes...
Abstract Ultrabroad spectrum detection has a wide range of photonic and optoelectronic applications, such as spectroscopy, optical communication, imaging, sensing. 3D topological insulator candidates are promising materials for fast high‐performance photodetectors owing to their linear dispersion band structure high carrier mobility. In this study, an ultrabroadband photothermoelectric (PTE) self‐powered detector based on the candidate HfTe 5 is reported first time. The photosensitive...
We report on nonlinear terahertz third-harmonic generation (THG) measurements YBa
We use time-domain terahertz spectroscopy to measure the low energy conductivity and magnons in RuCl$_3$ under external magnetic field. At zero field, an oscillation with a frequency of 0.62 THz is clearly observed spectrum below T$_N$, which identified as magnon excitation order state. The not affected by field $\textbf{H}_{DC}$ when it applied along c-axis, but suppressed within ab plane. More interestingly, component wave $\textbf{h}(t)$ perpendicular in-plane we observe another coherent...
The kagome magnet ${\mathrm{TbMn}}_{6}{\mathrm{Sn}}_{6}$ is a new type of topological material that known to support exotic quantum magnetic states. Experimental work has identified hosts Dirac electronic states could lead and Chern phases, but the optical response fermions its properties remain be explored. Here, we perform an spectroscopy measurement combined with first-principles calculations on single-crystal sample investigate associated phenomena. exhibits frequency-independent...
Here, the authors present a detailed investigation of electrodynamic response ternary chalcogenide Bi${}_{2}$Rh${}_{3}$Se${}_{2}$ (of parkerite type), which is putative charge density wave material. The study implements combination broadband optical conductivity and ultrafast pump-probe measurements photoinduced changes in reflectivity. Their provide compelling evidence that phase transition at 240 K not purely structural transition, rather, it linked to formation order.
1T'-TaTe2 exhibits an intriguing first-order structural phase transition at around 170 K. Understanding the electronic properties is a crucial way to comprehend origin of transition. We performed combined optical and ultrafast pump-probe study on compound across temperature. The leads abrupt changes both spectra relaxation dynamics. measurements revealed sudden reconstruction band structure. elaborate that first order can not be attributed conventional density-wave type instability. Our work...
We report near and mid-infrared pump c-axis terahertz probe measurement on a superconducting single crystal La$_{1.905}$Ba$_{0.095}$CuO$_4$ with T$_c$=32 K. The reveals that the pump-induced change occurs predominantly at Josephson plasma edge position below T$_c$. Upon excited by strong near-infrared pulses, state is severely disturbed incoherent quasiparticle excitations develop in frequency regime above static edge. However, within very short time delay ($\sim$1.5 ps) we observe...
Nonlinear responses of superconductors to intense terahertz radiation has been an active research frontier. Using pump-terahertz probe spectroscopy, we investigate the c-axis nonlinear optical response a high-temperature superconducting cuprate. After excitation by single-cycle pump pulse, reflectivity pulse oscillates as pump-probe delay is varied. Interestingly, oscillatory central frequency scales linearly with frequency, fact widely overlooked in experiments. By theoretically solving...
Intense laser pulses have recently emerged as a tool to tune between different orders in complex quantum materials. Among light-induced phenomena, transient superconductivity far above the equilibrium transition temperature cuprates is particularly attractive. Key those experiments was resonant pumping of specific phonon modes, which believed induce superconducting phase coherence by suppressing competing or modifying structure slightly. Here, we present comprehensive study photo-induced...
The ultrafast manipulation of quantum material has led to many novel and significant discoveries. Among them, the light-induced transient superconductivity in cuprates achieved by melting competing stripe orders represents a highly appealing accomplishment. However, recent investigations have shown that notion photoinduced remains topic controversy, its elucidation solely through <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"...
We report the investigation of spin dynamics in antiferromagnetic metal ${\mathrm{EuIn}}_{2}{\mathrm{As}}_{2}$ with Zintl phase by using time-resolved magneto-optical Kerr effect (TR-MOKE) and transient reflectivity spectroscopy. In TR-MOKE measurement, we observe a precession mode frequency about 18 GHz below 1.4 T new emerging coherent acoustic phonon near 35 at higher field where latter shows field-independent behavior. With temperature increasing, disappears above N\'eel ${T}_{N}$,...
Utilizing ultrafast light-matter interaction to manipulate electronic states of quantum materials is an emerging area research in condensed matter physics. It has significant implications for the development future devices. However, ability induce long-lasting metastable a fully reversible manner long-standing challenge. Here, by using laser excitations, we demonstrate capability polar charge-density-wave material EuTe
We report magnetotransport measurements of InSb/Al1-xInxSb modulation doped quantum well (QW) structures and the extracted transport lifetime carriers at low temperature consider conventional lifetimes over a range samples with different doping levels carrier densities, deduce regimes dependent on QW state filling calculated from self-consistent Schrödinger–Poisson modelling. For where only lowest subband is occupied electron densities cm−2 ps, ps are Shubnikov–de Haas oscillations below...
We report optical spectroscopy and ultrafast pump-probe measurements on the antiferromagnetic heavy fermion compound CePt$_2$In$_7$, a member showing stronger two dimensionality than other compounds in CeIn$_3$-derived heavy-fermion family. identify clear typical hybridization spectral structures at low temperature from different probes. However, strength related energy scale of are much weaker smaller that superconducting CeCoIn$_5$ CeIrIn$_5$. The features more similar to observations...
We report the significant enhancement on ultrafast terahertz optical conductivity and unexpected formation of a polaronic-like state in semiconductor Mn3Si2Te6 at room temperature. With absorption pump photons, low-frequency photoconductivity spectrum exhibits rise, quickly forming broad peak subsequently shifting to higher energy. The short-lived nature peak, as well distribution constants, strongly points towards transient polaron mechanism. Our study not only provides profound insights...