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We present high-order harmonic generation results obtained with different laser systems a 1 ps 1053 nm Nd-glass laser a 2 ps 616 nm synchronously pumped dye laser a 36 ps 1064 nm mode-locked Nd-YAG laser and the second harmonics (308 nm and 532 nm) of the latter two systems. We investigate the influence of the laser pulse width the excitation wavelength (from the near infrared to the ultraviolet)
Despite its simplicity and relevance for the description of electronic correlations in solids, the Hubbard model is seldom inarguably realized in real materials. Here, we show that monolayer Nb3Cl8 is an ideal candidate to be described within a single-orbital Hubbard model, constructed within a “molecular” rather than atomic basis set using ab initio constrained random phase approximation calculat
Nobelpriset 2023 Professor Anne L’Huillier, vid avdelningen för atomfysik på fysiska institutionen, belönades med Nobelpriset i fysik 2023 tillsammans med Pierre Agostini och Ferenc Krausz för deras experiment som gett mänskligheten nya verktyg för att utforska elektronernas värld inuti atomer och molekyler.Mer om Nobelpriset och Anne L´Hullier på LTH:s webbplats. Våra forskningsavdelningar Astrof
https://www.fysik.lu.se/forskning - 2026-07-13
Quantum mechanics forbids perfect discrimination of non-orthogonal states, a limitation that can be exploited to certify intrinsic randomness. Building on this principle, this thesis investigates how limits on state discrimination can be used to generate certified randomness in prepare-and-measure protocols. In particular, we study how the performance of minimum-error quantum state discrimination
Coupled cluster methods are compared to multiconfigurational second-order perturbation theory in a study of the high spin d(x)s(2) -> d(x+1)s(1) excitations in first, second, and third row transition metals. Large basis sets of the atomic natural orbital type are used. Scalar relativistic effects are included using the Douglas-Kroll-Hess Hamiltonian. The effect of spin-orbit coupling is demonstrat
Abstract is not available
We use a numerical model based on non-equilibrium Green's functions to investigate the influence of interface roughness (IFR) scattering in terahertz quantum cascade lasers. We confirm that IFR is an important phenomenon that affects both current and gain. The simulations indicate that IFR causes a leakage current that transfers electrons from the upper to the lower laser state. In certain cases,
Inverse problems are important in quantum mechanics and involve such questions as finding which potential give a certain spectrum or which arrangement of atoms give certain properties to a molecule or solid. Inverse problems are typically very hard to solve and tend to be very compute intense. We here show that neural networks can easily solve inverse problems in quantum mechanics. It is known tha
In a quantum-mechanical system, particle-hole duality implies that instead of studying particles, we can get equivalent information by studying the missing particles, the so-called holes. Using this duality picture for fermions in a rotating trap the vortices appear as holes in the Fermi sea. Here we predict that the formation of vortices in quantum dots at high magnetic fields causes oscillations
Forskningsadministrativ chef, avdelningen för fasta tillståndets fysik Kontaktinformation E-post: anneli [dot] lofgren [at] fysik [dot] lu [dot] se Telefon: +46 46 222 84 99 Mobil: +46 76 112 84 99Organisation Fasta tillståndets fysik Besöksadress: Professorsgatan 1, Lund Rumsnummer: Q282 Hämtställe: 14 WebbplatsAnneli Löfgrens profil i Lunds universitets forskningsportalAndra roller Biträdande av
https://www.fysik.lu.se/anneli-lofgren - 2026-07-14
Surface interactions of water with nano-TiO2 and structurally related group IV metal dioxide nanoparticles have been investigated using density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations. The investigated clusters include 46 and 92 unit models of TiO2 (i.e., (TiO2)(46) and (TiO2)(92)) of the three low-energy polymorphs of TiO2: anatase, rutile, and brookite. The investiga
Over the last decade it has been pointed out by several philosophers that not all Status Function Declarations are synchronic: some such declarations are directed toward the absolute past. Such Status Function Declarations are perplexing if one is an ontic realist with respect to institutional properties and states of affairs. If successful, such Status Function Declarations seem to change the absOver the last decade it has been pointed out by several philosophers that not all Status Function Declarations are synchronic: some such declarations are directed toward the absolute past. Such Status Function Declarations are perplexing if one is an ontic realist with respect to institutional properties and states of affairs. If successful, such Status Function Declarations seem to change the abs
Plasmonic materials have optical cross sections that exceed by 10-fold their geometric sizes, making them uniquely suitable to convert light into electrical charges. Harvesting plasmon-generated hot carriers is of interest for the broad fields of photovoltaics and photocatalysis; however, their direct utilization is limited by their ultrafast thermalization in metals. To prolong the lifetime of ho
Coherent radiation from a relativistic electron beam is a valuable way to overcome the present limitations of conventional lasers and synchrotron radiation light sources. The typical scheme has electrons, directly from a linac, in a single-pass interaction with a laser pulse in the presence of a static undulator magnetic field. We demonstrate that a storage-ring free-electron laser can also achiev
