Ultrafast Optical Control of the Electronic Properties of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>Zr</mml:mi><mml:msub><mml:mrow><mml:mi>Te</mml:mi></mml:mrow><mml:mrow><mml:mn>5</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>

Manzoni, Giulia; Sterzi, Andrea; Crepaldi, Alberto; Diego, Michele; Cilento, Federico; Zacchigna, M.; Bugnon, Philippe; Berger, H.; Magrez, Arnaud; Grioni, M.; Parmigiani, Fulvio

doi:10.1103/physrevlett.115.207402

Cited by 72 publications

(94 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The monolayer is also computed to be a 2D TI [10] and scanning tunneling microscopy/spectroscopy (STM/STS) experiments suggest the existence of topologically protected states at step edges [18,19]. However, the unambiguous identification of the topological phase of ZrTe 5 is still lacking.In this Letter we report on the STI character of the bulk ZrTe 5 by combining ab initio calculations and multiple experimental techniques, at temperature both above and below the one of the resistivity peak, T * ∼ 160 K [7][8][9]15]. Angleresolved photoelectron spectroscopy (ARPES) experiments in the ultraviolet (UV) and soft x-ray (SX) energy ranges reveal the presence of two distinct states at the top of the valence band (VB).…”

mentioning

confidence: 99%

“…ZrTe 5 has recently emerged as a challenging system with unique, albeit poorly understood, electronic properties [7][8][9][10][11][12][13][14][15][16][17]. Magneto-transport [11], magneto-infrared [13] and optical spectroscopy [14] studies describe ZrTe 5 in terms of a 3D Dirac semimetal.…”

mentioning

confidence: 99%

“…In this Letter we report on the STI character of the bulk ZrTe 5 by combining ab initio calculations and multiple experimental techniques, at temperature both above and below the one of the resistivity peak, T * ∼ 160 K [7][8][9]15]. Angleresolved photoelectron spectroscopy (ARPES) experiments in the ultraviolet (UV) and soft x-ray (SX) energy ranges reveal the presence of two distinct states at the top of the valence band (VB).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Evidence for a Strong Topological Insulator Phase in ZrTe5

et al. 2016

Self Cite

View full text Add to dashboard Cite

The complex electronic properties of ZrTe5 have recently stimulated in-depth investigations that assigned this material to either a topological insulator or a 3D Dirac semimetal phase. Here we report a comprehensive experimental and theoretical study of both electronic and structural properties of ZrTe5, revealing that the bulk material is a strong topological insulator (STI). By means of angle-resolved photoelectron spectroscopy, we identify at the top of the valence band both a surface and a bulk state. The dispersion of these bands is well captured by ab initio calculations for the STI case, for the specific interlayer distance measured in our x-ray diffraction study. Furthermore, these findings are supported by scanning tunneling spectroscopy revealing the metallic character of the sample surface, thus confirming the strong topological nature of ZrTe5.The discovery of topological insulators (TIs), characterized by metallic spin-polarized surface states connecting the bulk valence and conduction bands [1], has stimulated the search for novel topological phases of matter [2][3][4][5][6]. ZrTe 5 has recently emerged as a challenging system with unique, albeit poorly understood, electronic properties [7][8][9][10][11][12][13][14][15][16][17]. Magneto-transport [11], magneto-infrared [13] and optical spectroscopy [14] studies describe ZrTe 5 in terms of a 3D Dirac semimetal. Theoretical calculations have predicted its bulk electronic properties to lie in proximity of a topological phase transition between a strong and a weak TI (STI and WTI, respectively), where only the former displays topologically protected surface states at the experimentally accessible (010) surface [10]. The monolayer is also computed to be a 2D TI [10] and scanning tunneling microscopy/spectroscopy (STM/STS) experiments suggest the existence of topologically protected states at step edges [18,19]. However, the unambiguous identification of the topological phase of ZrTe 5 is still lacking.In this Letter we report on the STI character of the bulk ZrTe 5 by combining ab initio calculations and multiple experimental techniques, at temperature both above and below the one of the resistivity peak, T * ∼ 160 K [7][8][9]15]. Angleresolved photoelectron spectroscopy (ARPES) experiments in the ultraviolet (UV) and soft x-ray (SX) energy ranges reveal the presence of two distinct states at the top of the valence band (VB). On the basis of photon energy dependent studies, we ascribe the origin of these two states to the bulk and crystal surface, respectively. We have performed ab initio calculations of the topological phase diagram of ZrTe 5 , as a function of the interlayer distance b/2. Our measured band dispersion is in agreement with the calculations and it is consistent with the STI case for b/2 = 7.23 ± 0.02Å. This value has been confirmed for our specimen by x-ray diffraction (XRD) measurements. Furthermore, the 3D Dirac semimetal phase is not protected by crystalline symmetries, and it manifests only for the specific b/2 = 7.35Å at the boundar...

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Evidence for a Strong Topological Insulator Phase in ZrTe5

et al. 2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…In any case, possible causes for this behavior were advanced. These include density waves [3], inconsistent with the diffraction and high magnetic field data [4]; polaronic models [7], which are, however, apparently inconsistent with the good low-temperature conduction; a semimetal-semiconductor phase transition [8] or a temperature-induced Lifshitz transition [9,10]. More recently, these compounds have become of interest as topological materials whose low-energy electronic structure is controlled by spin-orbit interactions [11].…”

Section: Introductionmentioning

confidence: 99%

Bipolar Conduction as the Possible Origin of the Electronic Transition in Pentatellurides: Metallic vs Semiconducting Behavior

et al. 2018

View full text Add to dashboard Cite

The pentatellurides ZrTe 5 and HfTe 5 are layered compounds with one-dimensional transition-metal chains that show a not-yet-understood temperature-dependent transition in transport properties as well as recently discovered properties suggesting topological semimetallic behavior. Here, we report magnetotransport properties for two kinds of ZrTe 5 single crystals grown with the chemical vapor transport (CVT) and the flux method (Flux), respectively. They show distinct transport properties at zero field: The CVT crystal displays a metallic behavior with a pronounced resistance peak and a sudden sign reversal in thermopower at approximately 130 K, consistent with previous observations of the electronic transition; in striking contrast, the Flux crystal exhibits a semiconducting-like behavior at low temperatures and a positive thermopower over the whole temperature range. For both samples, strong effects on the transport properties are observed when the magnetic field is applied along the orthorhombic b and c axes, i.e., perpendicular to the chain direction. Refinements on the single-crystal x-ray diffraction and the measurements of energy dispersive spectroscopy reveal the presence of noticeable Te vacancies in the CVT samples, while the Flux samples are close to the stoichiometry. Analyses on the magnetotransport properties confirm that the carrier densities of the CVT sample are about two orders higher than those of the Flux sample. Our results thus indicate that the widely observed anomalous transport behaviors in pentatellurides actually take place in the Te-deficient samples. For the stoichiometric pentatellurides, our electronic structure calculations show narrow-gap semiconducting behavior, with different transport anisotropies for holes and electrons. For the degenerately doped n-type samples, our transport calculations can result in a resistivity peak and crossover in thermopower from negative to positive at temperatures close to those observed experimentally due to a combination of bipolar effects and different anisotropies of electrons and holes. Our present work resolves the long-standing puzzle regarding the anomalous transport behaviors of pentatellurides, as well as the electronic structure in favor of a semiconducting state.

show abstract

“…(45)] using the full spectral function of the system which includes quasiparticle and anomalous contributions. In the case of a superconductor, the full Green's function, and therefore the spectral function, can be conveniently written as a matrix in the Nambu basis (see Appendix E 2 a).…”

Section: Pumping: Excitonic Phasementioning

confidence: 99%

Excitonic instability in optically pumped three-dimensional Dirac materials

Pertsova

Balatsky

2018

Phys. Rev. B

View full text Add to dashboard Cite

Recently it was suggested that transient excitonic instability can be realized in optically-pumped two-dimensional (2D) Dirac materials (DMs), such as graphene and topological insulator surface states. Here we discuss the possibility of achieving a transient excitonic condensate in opticallypumped three-dimensional (3D) DMs, such as Dirac and Weyl semimetals, described by nonequilibrium chemical potentials for photoexcited electrons and holes. Similar to the equilibrium case with long-range interactions, we find that for pumped 3D DMs with screened Coulomb potential two possible excitonic phases exist, an excitonic insulator phase and the charge density wave phase originating from intranodal and internodal interactions, respectively. In the pumped case, the critical coupling for excitonic instability vanishes; therefore, the two phases coexist for arbitrarily weak coupling strengths. The excitonic gap in the charge density wave phase is always the largest one. The competition between screening effects and the increase of the density of states with optical pumping results in a reach phase diagram for the transient excitonic condensate. Based on the static theory of screening, we find that under certain conditions for the value of the dimensionless coupling constant screening in 3D DMs can be weaker than in 2D DMs. Furthermore, we identify the signatures of the transient excitonic condensate that could be probed by scanning tunneling spectroscopy, photoemission and optical conductivity measurements. Finally, we provide estimates of critical temperatures and excitonic gaps for existing and hypothetical 3D DMs.

show abstract

Ultrafast Optical Control of the Electronic Properties ofZrTe5

Cited by 72 publications

References 31 publications

Evidence for a Strong Topological Insulator Phase in ZrTe5

Evidence for a Strong Topological Insulator Phase in ZrTe5

Bipolar Conduction as the Possible Origin of the Electronic Transition in Pentatellurides: Metallic vs Semiconducting Behavior

Excitonic instability in optically pumped three-dimensional Dirac materials

Contact Info

Product

Resources

About