About

Hanyu Zhu, Ph.D., is an Associate Professor in Materials Science and NanoEngineering at Rice University, with joint appointments in Physics & Astronomy and Electrical & Computer Engineering. He holds a B.S. in Mathematics and Physics from Tsinghua University and earned his Ph.D. in Applied Science and Technology from the University of California at Berkeley. Professor Zhu's research focuses on lattice dynamics in quantum materials, ultrafast opto-electronics and electro-mechanics, low-dimensional structures and interfaces, and the development of OptoElectroMechanical sensors and actuators. His work explores fundamental physical phenomena and advanced material properties with applications in next-generation electronic and photonic devices.

Research topics

• Optoelectronics
• Chemistry
• Physics
• Materials science
• Condensed matter physics
• Nanotechnology
• Quantum mechanics
• Polymer chemistry
• Physical chemistry
• Photochemistry
• Engineering physics
• Chemical engineering
• Inorganic chemistry
• Crystallography

Selected publications

• Valleytronics: Fundamental Challenges and Materials Beyond Transition Metal Chalcogenides (Small 28/2025)

  Small · 2025-07-01

  articleOpen accessSenior author

  Valleytronics Valleytronics store information using electrons at different momentum spaces in the band structures, as illustrated by the red and blue pockets. The electronic states are protected from thermal scattering by having different spins in each pocket. The valley information can be written into and read from new materials like inorganic perovskite derivatives Cs3Bi2I9 by circularly polarized light. More in article number 2402139, Jia Liang, Hanyu Zhu, and co-workers.

  PublisherOA PDFDOI

• Comparative analysis of hyperspectral and near-infrared spectroscopy for bloodstain deposition time estimation

  Analytical Methods · 2025-01-01

  article

  BACKGROUND: Bloodstains are a prevalent and critical type of forensic evidence at crime scenes. Accurate determination of bloodstain age is essential for crime resolution, and non-destructive spectral methods are instrumental in this process. While extensive research has established the practicality of hyperspectral imaging (HSI) in specific forensic contexts, limited studies have explored near-infrared (NIR) spectroscopy. Owing to its superior penetration capabilities and high sensitivity, NIR holds promise in addressing certain limitations of HSI. This study aims to assess the applicability of NIR spectroscopy for bloodstain age estimation in forensic contexts and to compare its efficacy with HSI. RESULTS: Bloodstains were aged on various substrates over a 60 day period, with periodic analyses conducted using both spectral methods. Chemometric analysis of the spectral data was performed following SNV preprocessing and application of different regression algorithms. First, linear regression analysis was utilized to determine the effect of material on bloodstain deposition. Under the premise of distinguishing materials, partial least squares (PLS) regression was employed to extract eight latent variables from HSI and NIR spectral data for regression prediction. However, the prediction performance was suboptimal. To address this, polynomial features were introduced into the PLS regression algorithm to capture the nonlinear relationships in the spectral data, and the improved model significantly enhanced the prediction performance. Furthermore, PLS polynomial regression was applied to predict homologous data, and the results also demonstrated favorable performance. Finally, to optimize the prediction accuracy of multimodal data, a multilayer perceptron (MLP) was introduced for regression prediction through multimodal data fusion, further improving the overall performance of the model. Finally, predictive performance was evaluated across models, emphasizing their specific strengths. For homologous data fusion, comparable root mean square errors of prediction (RMSEP) were achieved for HSI and NIR spectra, at 8.35 and 8.15 days, respectively. Similar RMSEP values were observed in multimodal data fusion, and the accuracy of both low-level and intermediate-level fusion methods was evaluated. SIGNIFICANCE: HSI and NIR spectroscopy each provide unique advantages in bloodstain detection. Data fusion of these methods helps mitigate external influences, enhancing the approach's general applicability. This integrated method facilitates rapid estimation of bloodstain age at crime scenes, aiding in crime timeline determination and presenting valuable potential for forensic applications.

  PublisherDOI

• Lattice-induced spin dynamics in Dirac magnet CoTiO3

  ArXiv.org · 2025-08-28

  preprintOpen accessSenior author

  Spin-lattice coupling is crucial for understanding the spin transport and dynamics for spintronics and magnonics applications. Recently, cobalt titanate (CoTiO3), an easy-plane antiferromagnet, has been found to host axial phonons with a large magnetic moment, which may originate from spin-lattice coupling. Here, we investigate the effect of light-driven lattice dynamics on the magnetic properties of CoTiO3 using time-resolved spectroscopy with a THz pump and a magneto-optic probe. We found resonantly driven Raman active phonons, phonon-polariton-induced excitation of the antiferromagnetic magnons, and a slow increase in the polarization rotation of the probe, all indicating symmetry breaking that is not intrinsic to the magnetic space group. The temperature dependence confirmed that the observed spin dynamics is related to the magnetic order, and we suggest surface effects as a possible mechanism. Our results of THz-induced spin-lattice dynamics signify that extrinsic symmetry breaking may contribute strongly and unexpectedly to light-driven phenomena in bulk complex oxides.

  PublisherOA PDFDOI

• The second-order nonlinear optical properties of <i>κ</i>-phase gallium oxide

  APL Materials · 2025-10-01 · 4 citations

  articleOpen access

  In this study, we present the first characterization of the effective second-order nonlinear optical susceptibility χeff(2) and the second-order susceptibility tensor element d31 of κ-phase gallium oxide (κ-Ga2O3) using a second harmonic generation (SHG) technique. At the wavelength of 850 nm, we measured a χeff(2) value of 0.1068 pm/V and a d31 value of 0.0566 pm/V. In addition, we investigated the wavelength and polarization dependence of χeff(2). These findings could be a constructive step toward expanding the potential applications of Ga2O3 as a novel optical material platform, complementing its emerging role as a competitive next-generation material for electronics.

  PublisherDOI

• Chiral phonons

  Nature Physics · 2025-09-22 · 25 citations

  articleOpen accessCorresponding
  PublisherOA PDFDOI

• Spatiotemporally Controlled Soft Robotics with Optically Responsive Liquid Crystal Elastomers

  Advanced Intelligent Systems · 2025-06-01

  articleOpen accessSenior authorCorresponding

  Spatiotemporally Controlled Soft Robotics Artistic depiction of a robot with optically responsive liquid crystal elastomer limbs kicking a soccer ball in a grass field. The bending joints of the limbs are controlled remotely by front and back laser beams. The robotic face shield displays the schematic of a neural network collecting the limb configuration by machine vision and adjusting the laser patterns for desirable actions. More details can be found in article number 2500045 by Hanyu Zhu and co-workers.

  PublisherOA PDFDOI

• Lattice-induced spin dynamics in Dirac magnet CoTiO3

  Journal of Applied Physics · 2025-10-09 · 3 citations

  articleOpen accessSenior author

  Spin–lattice coupling is crucial for understanding the spin transport and dynamics for spintronics and magnonics applications. Recently, cobalt titanate (CoTiO3), an easy-plane antiferromagnet, has been found to host axial phonons with a large magnetic moment, which may originate from spin–lattice coupling. Here, we investigate the effect of light-driven lattice dynamics on the magnetic properties of CoTiO3 using time-resolved spectroscopy with a terahertz pump and a magneto-optic probe. We found resonantly driven Raman-active phonons, phonon–polariton-induced excitation of the antiferromagnetic magnons, and a slow increase in the polarization rotation of the probe, all indicating symmetry breaking that is not intrinsic to the magnetic space group. The temperature dependence confirmed that the observed spin dynamics is related to the magnetic order, and we suggest surface effects as a possible mechanism. Our results of THz-induced spin–lattice dynamics signify that extrinsic symmetry breaking may contribute strongly and unexpectedly to light-driven phenomena in bulk complex oxides.

  PublisherOA PDFDOI

• Spatiotemporally Controlled Soft Robotics with Optically Responsive Liquid Crystal Elastomers

  Advanced Intelligent Systems · 2025-04-15 · 3 citations

  articleOpen accessSenior authorCorresponding

  Light‐responsive materials enable the development of soft robots that are controlled remotely in 3D space and time without the need for cumbersome wires, onboard batteries, or altering the local environment. Azobenzene liquid crystal polymer networks are one such material that can move and deform in response to light actuation. Previous works have demonstrated azo‐based soft robotic grippers and transporters that are remotely powered by light. However, highly adaptive, automated spatiotemporal optical control over these materials has not yet been realized. Herein, a system for an azobenzene liquid crystal elastomer soft robotic arm is created by dynamically patterning light for independently maneuverable joints. The nonlinear material response to optical actuation is characterized, and the broad actuation space is explored with diverse arm configurations. A neural network is trained on the arm configurations and corresponding laser pattern to automate the pattern generation for a desired configuration. Finally, the azobenzene liquid crystal elastomer arm demonstrates complex targeted motion, marking an important step toward optically actuated soft robotics with applications ranging from optomechanics to biomedical tools.

  PublisherOA PDFDOI

• Influence of chromium intercalation in self-intercalated van der Waals magnets <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi mathvariant="normal">C</mml:mi><mml:msub><mml:mi mathvariant="normal">r</mml:mi><mml:mrow><mml:mn>1</mml:mn><mml:mo>+</mml:mo><mml:mi>δ</mml:mi></mml:mrow></mml:msub><mml:mi mathvariant="normal">T</mml:mi><mml:msub><mml:mi mathvariant="normal">e</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math>

  Physical Review Materials · 2025-09-26

  article
  PublisherDOI

• Chiral phonon-spin dynamics across van der Waals interface

  2025-01-01

  articleSenior author

  Using ultrafast terahertz pulses to resonantly excite chiral phonons in paramagnetic CeF 3 , we found long-lived magnetization is induced in adjacent ferromagnetic Cr 2 Ge 2 Te 6 , corresponding to an effective magnetic field of 1 T according to atomistic simulation.

  PublisherDOI

Recent grants

• CAREER: Probing Quantum Materials Modified by Terahertz Quantum Fluctuations

  NSF · $521k · 2023–2028

• Engineering quantum electronic materials by phonon-polariton metamaterials

  NSF · $450k · 2020–2024

• Collaborative Research: Understanding and Manipulating Magnetism and Spin Dynamics in Intercalated van der Waals Magnets

  NSF · $258k · 2024–2026

Frequent coauthors

• Rui Xu

  Rice University

  141 shared

• Pulickel M. Ajayan

  Rice University

  128 shared

• Yuji Zhao

  Rice University

  123 shared

• A. Glen Birdwell

  DEVCOM Army Research Laboratory

  121 shared

• Tony Ivanov

  DEVCOM Army Research Laboratory

  121 shared

• Anand B. Puthirath

  Rice University

  121 shared

• Róbert Vajtai

  Rice University

  120 shared

• Harikishan Kannan

  Rice University

  119 shared

Labs

• Zhu GroupPI

  Lattice dynamics in quantum materials; Ultrafast opto-electronics and electro-mechanics; Low-dimensional structures and interfaces; OptoElectroMechanical sensors and actuators.

Education

• PhD, Applied Science & Technology

  University of California Berkeley

  2016

• BS, Physics

  Tsinghua University

  2011