skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.


Title: Quantum Composites with Charge‐Density‐Wave Fillers
Abstract A unique class of advanced materials—quantum composites based on polymers with fillers composed of a van der Waals quantum material that reveals multiple charge‐density‐wave quantum condensate phases—is demonstrated. Materials that exhibit quantum phenomena are typically crystalline, pure, and have few defects because disorder destroys the coherence of the electrons and phonons, leading to collapse of the quantum states. The macroscopic charge‐density‐wave phases of filler particles after multiple composite processing steps are successfully preserved in this work. The prepared composites display strong charge‐density‐wave phenomena even above room temperature. The dielectric constant experiences more than two orders of magnitude enhancement while the material maintains its electrically insulating properties, opening a venue for advanced applications in energy storage and electronics. The results present a conceptually different approach for engineering the properties of materials, extending the application domain for van der Waals materials.  more » « less
Award ID(s):
1921958
PAR ID:
10413949
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  ;  ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Advanced Materials
Volume:
35
Issue:
19
ISSN:
0935-9648
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Abstract We report the results of polarization‐dependent Raman spectroscopy of phonon states in single‐crystalline quasi‐one‐dimensional NbTe4and TaTe4van der Waals materials. The measurements were conducted in the wide temperature range from 80 to 560 K. Our results show that although both materials have identical crystal structures and symmetries, there is a drastic difference in the intensity of their Raman spectra. While TaTe4exhibits well‐defined peaks through the examined wavenumber and temperature ranges, NbTe4reveals extremely weak Raman signatures. The measured spectral positions of the phonon peaks agree with the phonon band structure calculated using the density‐functional theory. We offer possible reasons for the intensity differences between the two van der Waals materials. Our results provide insights into the phonon properties of NbTe4and TaTe4van der Waals materials and indicate the potential of Raman spectroscopy for studying charge‐density‐wave quantum condensate phases. 
    more » « less
  2. Recently a new research field of quasi-one-dimensional (1D) van der Waals quantummaterials has emerged from earlier work on low-dimensional systems [1-2]. The quasi-1D van der Waalsmaterials have 1D motifs in their crystal structure [1]. Many of these materials reveal strongly correlatedphenomena such as charge density waves (CDW) [1-2]. The CDW phase is a periodic modulation of theelectronic charge density, accompanied by distortions in the underlying crystal lattice. Potential uses for CDWmaterials include memory storage and oscillators [3]. Raman spectroscopy can identify the CDW transitions todifferent phases via the appearance of phonon peaks due to emerging superstructure or the disappearance ofcertain peaks due to the loss of translation symmetry in the crystal lattice [3]. In this presentation, we report theresults of the angle and temperature-dependent Raman scattering spectroscopy investigation of themechanically exfoliated nanowires of the quasi-1D Nb van der Waals material. It is known that Nb forms in atetragonal crystal structure with space group 124 (P4/mcc). Recently, this material attracted attention as aCDW material with multiple phase transitions, some of them, possibly, near room temperature. Littleinformation is known on the Raman characteristics of this material. Our Raman data for different polarizationangles show strong anisotropy in the response depending on the crystal direction. The most pronouncedRaman peaks reveal strong temperature dependence. The results of the measurements will be compared withthe theoretical predictions. Our data is important for further investigation of this quasi-1D CDW material forpossible applications in phase-change memory and reconfigurable devices. A.A.B. acknowledges the support of the Vannevar Bush Faculty Fellowship (VBFF) from the Office of NavalResearch (ONR) contract N00014-21-1-2947 “One-Dimensional Quantum Materials” and the National ScienceFoundation (NSF) program Designing Materials to Revolutionize and Engineer our Future (DMREF) via aproject DMR-1921958 “Data-Driven Discovery of Synthesis Pathways and Distinguishing ElectronicPhenomena of 1D van der Waals Bonded Solids”. A. D. and S. K. acknowledge support through the MaterialGenome Initiative funding allocated to the National Institute of Standards and Technology. [1] A. A. Balandin, F. Kargar, T. T. Salguero, and R. Lake, “One-dimensional van der Waals quantummaterials", Mater. Today, 55, 74 (2022). [2] A. A. Balandin, R. K. Lake, and T. T. Salguero, "One-dimensional van der Waals materials - Advent of a newresearch field" Appl. Phys. Lett., 121, 040401 (2022). [3] A. A. Balandin, S. V. Zaitzev-Zotov, and G. Grüner, "Charge-density-wave quantum materials and devices—New developments and future prospects", Appl. Phys. Lett., 119, 170401 (2021). [4] R. Samnakay, et al., “Zone-folded phonons and the charge-density-wave transition in 1T-TaSe2 thin films, Nano Lett., 15, 2965 (2015). 
    more » « less
  3. Abstract Body: Recently a new research field of quasi-one-dimensional (1D) van der Waals quantummaterials has emerged from earlier work on low-dimensional systems [1-2]. The quasi-1D van der Waalsmaterials have 1D motifs in their crystal structure [1]. Many of these materials reveal strongly correlatedphenomena such as charge density waves (CDW) [1-2]. The CDW phase is a periodic modulation of theelectronic charge density, accompanied by distortions in the underlying crystal lattice. Potential uses for CDWmaterials include memory storage and oscillators [3]. Raman spectroscopy can identify the CDW transitions todifferent phases via the appearance of phonon peaks due to emerging superstructure or the disappearance ofcertain peaks due to the loss of translation symmetry in the crystal lattice [3]. In this presentation, we report theresults of the angle and temperature-dependent Raman scattering spectroscopy investigation of themechanically exfoliated nanowires of the quasi-1D Nb van der Waals material. It is known that Nb forms in atetragonal crystal structure with space group 124 (P4/mcc). Recently, this material attracted attention as aCDW material with multiple phase transitions, some of them, possibly, near room temperature. Littleinformation is known on the Raman characteristics of this material. Our Raman data for different polarizationangles show strong anisotropy in the response depending on the crystal direction. The most pronouncedRaman peaks reveal strong temperature dependence. The results of the measurements will be compared withthe theoretical predictions. Our data is important for further investigation of this quasi-1D CDW material forpossible applications in phase-change memory and reconfigurable devices. A.A.B. acknowledges the support of the Vannevar Bush Faculty Fellowship (VBFF) from the Office of NavalResearch (ONR) contract N00014-21-1-2947 “One-Dimensional Quantum Materials” and the National ScienceFoundation (NSF) program Designing Materials to Revolutionize and Engineer our Future (DMREF) via aproject DMR-1921958 “Data-Driven Discovery of Synthesis Pathways and Distinguishing ElectronicPhenomena of 1D van der Waals Bonded Solids”. A. D. and S. K. acknowledge support through the MaterialGenome Initiative funding allocated to the National Institute of Standards and Technology. [1] A. A. Balandin, F. Kargar, T. T. Salguero, and R. Lake, “One-dimensional van der Waals quantummaterials", Mater. Today, 55, 74 (2022). [2] A. A. Balandin, R. K. Lake, and T. T. Salguero, "One-dimensional van der Waals materials - Advent of a newresearch field" Appl. Phys. Lett., 121, 040401 (2022). [3] A. A. Balandin, S. V. Zaitzev-Zotov, and G. Grüner, "Charge-density-wave quantum materials and devices—New developments and future prospects", Appl. Phys. Lett., 119, 170401 (2021). [4] R. Samnakay, et al., “Zone-folded phonons and the charge-density-wave transition in 1T-TaSe2 thin films,” Nano Lett., 15, 2965 (2015). 
    more » « less
  4. Abstract TiSe2is an exciting material because it can be tuned between superconducting and charge density wave (CDW) transitions. In the monolayer limit, TiSe2exhibits a sizable energy gap in the CDW phase that makes it a promising quantum material. It is shown that interfacing a single layer of TiSe2with dissimilar van der Waals materials enables control of its properties. Using angle‐resolved photoemission spectroscopy, the energy gap opening is analyzed as a function of temperature for TiSe2monolayers supported on different van der Waals substrates. A substantial increase in the CDW transition temperature of ≈45 K is observed on MoS2compared to graphite (highly oriented pyrolytic graphite) substrates. This control of the CDW in monolayer TiSe2is suggested to arise from varying charge screening of the unconventional CDW of TiSe2by the substrate. In addition, the suppression of CDW order and a complete closing of the energy gap by electron doping of monolayer TiSe2is demonstrated. Regulating the many‐body physics phenomena in monolayer TiSe2lays the foundation of modifying TiSe2in, for example, artificial van der Waals heterostructures and thus creates a new approach for utilizing the quantum states of TiSe2in device applications. 
    more » « less
  5. Low-frequency electronic noise in charge-density-wave van der Waals materials has been an important characteristic, providing information about the material quality, phase transitions, and collective current transport. However, the noise sources and mechanisms have not been completely understood, particularly for the materials with a non-fully gapped Fermi surface where the electrical current includes components from individual electrons and the sliding charge-density wave. We investigated noise in nanowires of quasi-one-dimensional NbSe3, focusing on a temperature range near the Pearls transition TP1 ∼ 145 K. The data analysis allowed us to separate the noise produced by the individual conduction electrons and the quantum condensate of the charge density waves before and after the onset of sliding. The noise as a function of temperature and electric bias reveals several intriguing peaks. We explained the observed features by the depinning threshold field, the creep and sliding of the charge density waves, and the possible existence of the hidden phases. It was found that the charge density wave condensate is particularly noisy at the moment of depinning. The noise of the collective current reduces with the increasing bias voltage in contrast to the noise of the individual electrons. Our results shed light on the behavior of the charge density wave quantum condensate and demonstrate the potential of noise spectroscopy for investigating the properties of low-dimensional quantum materials. 
    more » « less