Quantum Materials
& Nanodevices
Laboratory
We explore the frontiers of condensed matter physics — from one-dimensional van der Waals crystals to high-temperature superconductors — using precision nanofabrication and low-temperature transport measurements.
Where Quantum Matter
Meets Its Limits
1D Quantum Physics in vdW Crystals
Probing Luttinger liquid behavior, spin-charge separation, and correlated ground states in atomically thin molecular chain nanowires.
Quantum Phase Transitions at the 2D Limit
Using thickness as a tuning parameter to reveal BKT transitions, quantum metallic states, and inhomogeneous superconductivity in atomically thin crystals.
Decoupling Order Parameters in Correlated Oxides
Disentangling coupled electronic and structural transitions across the rutile-structured transition metal oxide family using precision nanoscale tuning.
Novel Boundary States in Topological Materials
Uncovering surface and edge states protected by topology and crystal symmetry through precision low-temperature transport measurements.
Quantum Interactions in Low-Symmetry Layered vdW Materials
Investigating how strongly directional electron-phonon coupling in anisotropic layered crystals drives charge density waves, excitonic insulators, and unconventional superconductivity.
Research Areas
We combine nanofabrication, cryogenic transport measurements, spectroscopy, and first-principles calculations to investigate quantum phenomena at reduced dimensions.
One-Dimensional Quantum Physics in van der Waals Crystals
One-dimensional electron systems are fundamentally different from their three-dimensional counterparts. Electron-electron interactions completely reshape the ground state, giving rise to phenomena such as spin-charge separation, Luttinger liquid behavior, and collective charge density waves that have no analog in higher dimensions. We exploit a class of van der Waals crystals whose bulk structure consists of parallel molecular chains bound by weak inter-chain van der Waals forces. Because the inter-chain coupling is so weak, these crystals can be mechanically exfoliated all the way down to single or few-chain nanowires with atomic-scale cross-sections — the closest experimental realization of a truly one-dimensional conductor available in solid-state systems.
Using these systems, we investigate how extreme dimensional confinement shapes electronic transport, electron-phonon coupling, thermal conduction, and correlated ground states. Our studies have revealed ultralong ballistic phonon propagation, unusual anisotropic electron-phonon interactions, and signatures of excitonic insulator behavior in the monolayer limit — each reflecting the profound consequences of reduced dimensionality on quantum many-body physics. Materials such as Ta₂Pd₃Se₈, Ta₂Ni₃Se₈, and Ta₂Ni₃Te₅ serve as model systems.
Quantum Phase Transitions at the Two-Dimensional Limit
When a material is thinned to the atomic scale, thermal fluctuations are enhanced, symmetry can be broken in new ways, and phases masked in three dimensions can emerge. Superconductivity in two dimensions is a particularly rich arena: rather than a sharp mean-field transition, 2D superconductors undergo a Berezinskii–Kosterlitz–Thouless transition driven by vortex-antivortex unbinding, and near the transition a mysterious quantum metallic state can appear whose origin remains debated.
Our approach is to use precision nanofabrication to reduce bulk crystals to the 2D limit, treating thickness as a continuous tuning parameter. This has allowed us to reveal enhanced quantum coherence in atomically thin conductors, expose nanoscale inhomogeneous superconductivity hidden beneath bulk averaging, and probe how competing electronic phases respond to electrostatic gating and reduced screening. Iron-based chalcogenides and layered transition metal compounds serve as representative platforms.
Decoupling Order Parameters in Metal-Insulator Transitions
In strongly correlated materials, charge, spin, lattice, and orbital degrees of freedom are simultaneously active and deeply entangled. A first-order metal-insulator transition typically involves a simultaneous change of electronic state and crystal structure, making it difficult to determine which drives which. We address this by studying the transition at the nanoscale, where single-domain samples eliminate grain-boundary averaging and precise tuning parameters — chemical doping, electrostatic gating, applied strain — can be applied independently. Our work has demonstrated that the metallic phase can be stabilized without triggering a structural transition, pointing to a general principle: coupled order parameters can be disentangled when the right control knob is found.
We are particularly interested in extending this program across the broader family of rutile-structured transition metal oxides, which share a common crystal architecture yet span a remarkable range of electronic behavior — from metals to Mott insulators — depending on the choice of transition metal. The rutile structure provides a natural comparative framework for understanding how electron-electron interactions, electron-lattice coupling, and orbital occupation together determine the nature of the transition. Beyond its fundamental interest, controlling this interplay has implications for ultrafast switching and neuromorphic device applications.
Novel Boundary States in Topological Materials
Topological materials exhibit electrical properties protected by crystal symmetry and energy band topology, making their electronic characteristics substantially more robust than conventional materials. This robustness is further underscored by the emergence of novel two-dimensional surface states in three-dimensional topological materials.
Our work focuses on probing novel boundary states — surface states, edge states, and other topologically non-trivial modes — that arise at the boundaries of topological materials. These can be protected by bulk topology, crystal symmetry, or mechanisms outside conventional topological classification. A striking example is our discovery of a "floating" surface band in a nonsymmorphic semimetal: topologically trivial by standard criteria, yet exhibiting high-mobility two-dimensional quantum oscillations stabilized by a distinct symmetry-based protection mechanism. In quasi-one-dimensional topological materials, edge states along the chain direction offer a further frontier where topology, interactions, and reduced dimensionality intersect. We investigate these phenomena through precision nanofabrication and low-temperature electrical transport measurements.
Quantum Interactions in Low-Symmetry Layered van der Waals Materials
Distinct from the truly one-dimensional chain crystals of our first research area, this program focuses on layered van der Waals materials that are two-dimensional in their stacking character — but whose atomic structure within each layer is highly anisotropic and corrugated, forming quasi-one-dimensional motifs in the plane. This in-plane structural anisotropy gives rise to electron-phonon interactions that are strongly directional in momentum space: phonons couple intensely to electrons along specific crystalline directions while remaining nearly decoupled perpendicular to them. This is not a subtle correction to isotropic physics, but a qualitatively different regime that classical Raman scattering theory and conventional models of electron-phonon coupling are not equipped to capture.
Such anisotropic electron-phonon interactions carry deep consequences for emergent quantum phases within the layer. Selective coupling along particular momentum directions can drive Fermi surface instabilities that seed charge density waves, favor excitonic insulator condensation through amplified electron-hole attraction, or stabilize unconventional superconducting pairing. We investigate the nature, origin, and consequences of these interactions by combining angle-resolved polarized Raman spectroscopy, low-temperature transport measurements, and first-principles calculations to map the momentum-resolved coupling landscape and connect it to the correlated phases it produces.
The Group
Jiang Wei, Ph.D.
Department of Physics and Engineering Physics
Tulane University · New Orleans, Louisiana
Dr. Wei's research focuses on quantum transport in low-dimensional materials, including van der Waals 1D crystals, 2D superconductors, topological semimetals, and strongly correlated oxides. His lab combines nanofabrication, cryogenic electrical measurements, and materials synthesis to investigate fundamental quantum phenomena.
| Name | Current Position / Organization |
|---|---|
| Keyuan Bai | Tulane University |
| Jin Hu | University of Arkansas |
| Xue Liu | Anhui University |
| Chunlei Yue | ASML |
| Yun Lin | Suzhou University of Science & Technology |
| George Smith | Lockheed Martin |
| Jake Smith | PsiQuantum |
| Roland Harvey | E-space |
| Matthew J. Gorban | Rhea Space Activity |
| James Wesley Hendren | — |
| Sydney Marler | SpaceX |
| Chase Schober | Tesla |
| Julian George Willingham | Mirion Technologies, Inc. |
| Nicholas Della Fera | Beansprouts Inc. of Brooklyn |
| Zheng Huang | University of Illinois Chicago |
| Aryeh Krischer | Columbia University |
| Gavin Blair | University of Maryland |
| Jason Li | Blue Origin |
| Andrew Steely | Northrop Grumman |
| Nirasha Thilakaratne | Global Communication Semiconductors |
| Abin Joshy | INTEL |
News
Recent highlights from the Wei Lab.
Welcome to Declan Gorman, Theodore Frank, and Jasper Newton, who join the lab this summer as undergraduate research assistants!
Welcome to Liam Figueroa, who joins the lab as an undergraduate research assistant!
New paper: Unusual Electron-Phonon Interactions in Highly Anisotropic Two-Dimensional Ta₂Ni₃Te₅ — Wang et al., arXiv:2506.05809.
New paper: Scalable synthesis of millimeter-long single crystal Ta₂Ni₃Se₈ Van der Waals nanowires — Joshy et al., published in Scientific Reports.
New review: Unlocking the Potential of 1D M₂X₃Y₈ Ternary Transition Metal Chalcogenides — Antipina et al., Nano Letters.
Welcome, Sidrah Younus Khan, a new member of our team!
Congratulations to Abin Joshy on his successful dissertation defense!
The STEM outreach provided by the Tulane Cleanroom for Mount Carmel Academy's STREAM day was a great success. Read more →
In collaboration with Naguib's group, our work on Transition Metal Carbo-Chalcogenide (TMCC) — a new family of 2D materials — was featured in Advanced Materials. Read the paper →
Our study on ZrSiSe's "floating surface state" was published in Nano Letters. Read the paper →
Publications
Selected peer-reviewed articles and preprints from the Wei Lab.
Facilities
Our research is supported by state-of-the-art nanofabrication and measurement capabilities at Tulane University.
Tulane Cleanroom
Access to Tulane's shared cleanroom facilities for photolithography, electron-beam lithography, thin-film deposition, and reactive ion etching for nanodevice fabrication.
Cryogenic Transport
Low-temperature electrical transport measurement systems including a dilution refrigerator capable of reaching 50 mK and high magnetic fields for quantum transport studies. Our cryogenic instruments include:
- Quantum Design Dynacool PPMS
- Dilution Refrigerator (50 mK)
- Montana Instruments Cryostation Optical Cryostat
Scanning Electron Microscopy
High-resolution SEM and FIB systems for imaging, characterization, and focused-ion-beam processing of nanoscale devices and materials.
Crystal Growth & Synthesis
Chemical vapor transport and flux growth systems for synthesizing high-quality single crystals of van der Waals materials, topological semimetals, and correlated oxides.
For more information about Tulane's shared research facilities, please visit the Tulane School of Science & Engineering.
Join the Team
We are always looking for enthusiastic, talented researchers at all levels to join our group. We welcome people with backgrounds in physics, engineering, materials science, and related fields.
Postdoctoral Scholar
We seek enthusiastic postdocs with a research focus on nanodevices utilizing innovative low-dimensional quantum materials. Applicants should have a solid background in condensed matter physics with expertise in low-temperature transport measurement and nanofabrication.
Visiting Scholar
Scholars eager to explore diverse research opportunities or collaborate to address critical physics challenges in condensed matter physics and materials science are welcome to inquire about visiting positions.
Graduate Research Assistant
Positions are available for graduate students who possess a keen enthusiasm for nanoscale physics. Students from the Physics & Engineering Physics program and related departments are encouraged to reach out.
Undergraduate Research Assistant
Positions are available for undergraduate students with a science or engineering background. Proficiency in coding tools such as LabVIEW, MATLAB, or SolidWorks is highly desirable, as is experience or interest in machining and smart manufacturing.
Get in Touch
For direct inquiries about joining the lab, please send an email to Prof. Wei.
jwei1@tulane.edu