Technique - (7) Attosecond / femtosecond multidimensional spectroscopy

Type: Experimental

Description: Ultrashort pulse spectroscopies (transient absorption, 2D-ES, attosecond transient absorption) to probe electron and nuclear dynamics on fs–as timescales.

Department(s)/lab(s): Electrical & Electronic Engineering – Photon Science Institute | Boland Group (THz Semiconductor and 2D Materials Spectroscopy) @ Manchester
Summary:

Boland's group focuses on THz spectroscopy of semiconductor nanostructures and 2D materials for quantum sensing applications. Research directions: (1) THz optical pump–THz probe spectroscopy β€” measuring ultrafast carrier dynamics in semiconductor nanowires, quantum wells, and 2D materials (graphene, TMDs, perovskites) after optical excitation; (2) Near-field THz nanoscopy β€” sub-wavelength THz imaging of carrier distributions and quantum phase domains; (3) THz-active quantum devices β€” studying exciton and polaron dynamics in perovskite and III-V semiconductors at THz frequencies; (4) 2D material sensors β€” graphene-based THz detectors and emitters. Applications in quantum-material characterization and quantum sensing.

Department(s)/lab(s): Chemistry | Gaynor Group (Ultrafast & Attosecond Spectroscopy) @ Northwestern
Summary:

Prof. Gaynor (Chemistry, joined summer 2023) develops cutting-edge ultrafast spectroscopy at the physics-chemistry frontier. Directions: (1) Attochemistry β€” new ultrafast laser spectroscopies operating on attosecond to femtosecond timescales to directly measure how electron spin and orbital motion couple to molecular geometry (spin-vibronic coupling) in chiral molecules and materials of interest for energy conversion and spintronics; (2) Multidimensional nonlinear spectroscopy (2D electronic spectroscopy, 2D vibrational) to track energy and charge transfer immediately after photoexcitation; (3) Instrumentation-first approach: building novel attosecond transient absorption and correlation spectroscopy apparatus from scratch, enabling entirely new observables (e.g., electron-nuclear and spin-orbital correlations). INQUIRE faculty affiliate. Beckman Young Investigator 2025 ($600k, 4 yrs); Packard Fellow 2025 ($875k, 5 yrs).

Department(s)/lab(s): Electrical & Electronic Engineering – Photon Science Institute | Halsall Group (Photonics and Semiconductor Spectroscopy) @ Manchester
Summary:

Halsall is a senior PSI photonics researcher focusing on semiconductor spectroscopy and photonic quantum device characterization. Research directions: (1) Deep-level transient spectroscopy (DLTS) β€” characterizing defects and impurities in semiconductor quantum device structures (Si, GaN, SiC) that are relevant to qubit coherence; (2) Photoluminescence mapping β€” spatial mapping of optical quality in quantum well and dot wafers for quantum sensing device development; (3) InGaN/GaN quantum wells β€” non-destructive optical characterization of LED and sensor structures; (4) THz and infrared spectroscopy β€” contactless Hall measurements and Drude response for quantum material characterization. Provides photonic metrology tools for characterizing quantum sensing device materials.

Department(s)/lab(s): Physics & Astronomy – Photon Science Institute | Hibberd Group (THz Spectroscopy and Quantum Materials) @ Manchester
Summary:

Hibberd holds an EPSRC Ernest Rutherford Fellowship at Manchester's PSI. Research directions: (1) Ultrafast THz spectroscopy of magnetic materials β€” probing spin dynamics, magnon modes, and phase transitions in correlated magnetic materials with sub-ps time resolution using intense THz pulses; (2) THz-driven spintronics β€” using THz electric and magnetic fields to switch magnetization and induce spin currents; (3) THz generation from spintronic heterostructures β€” using ultrafast spin-charge conversion as a broadband THz emitter for materials characterization; (4) Quantum magnonics β€” studying collective spin excitations (magnons) as quantum sensors of materials order parameters. Bridges ultrafast optics and quantum sensing of magnetic phases.

Department(s)/lab(s): Chemistry and Physics | Leone Ultrafast X-ray Group @ UCB
Summary:

Leone's group generates attosecond and few-femtosecond XUV/X-ray pulses to track electron dynamics and charge migration in molecules and materials in real time, pushing time-domain spectroscopy toward the natural timescale of electronic motion.

Department(s)/lab(s): Physics & Astronomy – Photon Science Institute | Parkinson Group (Ultrafast Spectroscopy of Photonic Materials) @ Manchester
Summary:

Parkinson's group uses ultrafast optical spectroscopy to study carrier dynamics in photonic materials with quantum device applications. Research directions: (1) Time-resolved photoluminescence β€” TRPL with single-photon counting to map exciton lifetimes, diffusion, and defect trapping in GaN, perovskite, and 2D semiconductor quantum wells; (2) Optical single-particle spectroscopy β€” isolating single nanowires or nanocrystals for defect-free measurements of intrinsic optical properties; (3) Photon-number statistics β€” Hanbury Brown–Twiss measurements of single-photon purity from quantum dots and localized excitons; (4) Semiconductor quantum sensing interfaces β€” studying how carrier dynamics affect the fidelity of semiconductor-based quantum sensors and emitters.

Department(s)/lab(s): Chemistry | Scholes Group @ Princeton
Summary:

Scholes uses multidimensional ultrafast and coherence spectroscopies to probe wavepacket dynamics and quantum-mechanical phenomena in photosynthetic light-harvesting complexes, cavity QED, and photo-activated chemistry, including his group's resolution of a decade-long controversy over long-lived coherent coupling in the Fenna-Matthews-Olson complex. His current work extends coherence spectroscopy to quantum information science and photobiomodulation, squarely fitting the fundamental light-physics/quantum-optics side of the filter.