Phys.org August 26, 2024 Anisotropic planar polaritons – hybrid electromagnetic modes mediated by phonons, plasmons, or excitons – in biaxial two-dimensional (2D) van der Waals crystals have attracted significant attention due to their fundamental physics and potential nanophotonic applications. An international team of researchers (USA – University of Minnesota, Auburn University, Purdue University, City University of New York, IBM T. J. Watson Research Center, Vanderbilt University, Republic of Korea, Spain) reviewed the properties of planar hyperbolic polaritons and methods that could be used to experimentally tune them. They argued that such natural, planar hyperbolic media should be common in biaxial […]
Tag Archives: Polaritons
The forbidden propagation of hyperbolic phonon polaritons and applications in near-field energy transport
Phys.org July 8, 2024 GHz burst-mode femtosecond (fs) laser provides distinct characteristics in materials processing as compared with the conventional irradiation scheme of fs laser (single-pulse mode). Researchers in Japan used the moderate pulse interval of 205 ps in the burst pulse for high-quality and high-efficiency micromachining of single crystalline sapphire by laser induced plasma assisted ablation (LIPAA). The preceding pulses in the burst generated plasma by ablation of copper placed behind the sapphire substrate, which interacted with the subsequent pulses to induce ablation at the rear surface of sapphire substrates. The ablation quality, efficiency, and the fabrication resolution were […]
On-chip GHz time crystals with semiconductor photonic devices pave way to new physics and optoelectronic applications
Phys.org May 31, 2024 Time crystals (TCs) are many-body systems that display spontaneous breaking of time translation symmetry. An international team of researchers (Argentina, Germany) demonstrated a TC by using driven-dissipative condensates of microcavity exciton-polaritons, spontaneously formed from an incoherent particle bath. The TC phases were controlled by the power of a continuous-wave nonresonant optical drive exciting the condensate and the interaction with cavity phonons. The TC phases were, for increasing power, locking of the frequency of precession to self-sustained coherent phonons—stabilized TC; and doubling of TC’s period by phonons. According to the researchers the results established microcavity polaritons as […]
Scientists trap light inside a magnet
Science Daily August 16, 2023 Recent studies were able to modify some of the most defining features of light utilizing the strong coupling of light and matter in optical cavities. An international team of researchers (City College of New York, City University of New York, University of Washington, University of Michigan, MIT, Spain) studied the magneto-optical properties of a van der Waals magnet that supports strong coupling of photons and excitons even in the absence of external cavity mirrors. In the layered magnetic semiconductor CrSBr polaritons were shown to substantially increase the spectral bandwidth of correlations between the magnetic, electronic, […]
New breakthrough shows how short pulses of light destroy particles
Phys.org July 6, 2023 Molecular polaritons are hybrid light-matter states that emerge when a molecular transition strongly interacts with photons in a resonator. At optical frequencies, this interaction unlocks a way to explore and control new chemical phenomena at the nanoscale. However achieving such control at ultrafast timescales is challenging as it requires a deep understanding of the dynamics of the collectively coupled molecular excitation and the light modes. An international team of researchers (Germany, Italy, Sweden, Spain, Luxembourg) investigated the dynamics of collective polariton states, realized by coupling molecular photoswitches to optically anisotropic plasmonic nanoantennas. Pump-probe experiments revealed an […]
Proposed perovskite-based device combines aspects of electronics and photonics
Phys.org May 12, 2023 Hybrid perovskites have emerged as a promising material candidate for exciton-polariton (polariton) optoelectronics. Many applications demand precise control of polariton interactions. Thus far, the primary mechanisms by which polaritons relax in perovskites remain unclear. An international team of researchers (USA – MIT, Spain, Italy) sandwiched perovskite in between two precisely spaced reflective surfaces and stimulated them with laser beams. Then they were able to directly control the momentum of exciton-polariton pairs. The combined sate could be perturbed either with light or charge in a more energy-efficient manner. Halide perovskites harvest light well, and turn photons into […]
Atomically-smooth gold crystals help to compress light for nanophotonic applications
Phys.org July 13, 2022 An international team of researchers (South Korea, Denmark, Switzerland, Japan, USA – University of Minnesota) used a highly sensitive scanning near-field optical microscope (SNOM) to directly measure the optical fields of the hyperbolic image phonon-polaritons (HIP) propagating in a 63 nm-thick slab of hexagonal boron nitride (h-BN) on a monocrystalline gold substrate, showing the mid-infrared light waves in dielectric crystal compressed by a hundred times. They showed that the phonon-polaritons in van der Waals crystals can be significantly more compressed without sacrificing their lifetime. Practically zero surface scattering and extremely small ohmic loss in gold at […]
More efficient optical quantum gates
Phys.org May 13, 2022 Progress in optical quantum information processing is hampered by the low efficiency of the two-qubit quantum gates realized so far. Researchers in Germany demonstrated an optical two-qubit gate with an average efficiency above 40%, thus outperforming the previous record by a factor of almost 4. They accomplished this with electromagnetically induced transparency. Incoming photons are converted into polaritons in highly excited Rydberg state. Any two atoms in such a state have a strong interaction, even at large separations. When two photons enter the resonator, both become polaritons and their Rydberg components interact. When the excitations leave […]
Discovery of matter-wave polaritons sheds new light on photonic quantum technologies
Phys.org April 6, 2022 Exploiting the interaction between polaritons has led to the realization of superfluids of light as well as of strongly correlated phases in the microwave domain, with similar efforts underway for microcavity excitons–polaritons. Researchers at Stony Brook University have developed an ultracold-atom analogue of an exciton–polariton system in which interacting polaritonic phases can be studied with full tunability and in the absence of dissipation. In their optical lattice system, they replaced exciton by an atomic excitation, whereas an atomic matter wave was substituted for the photon under a strong dynamical coupling between the two constituents that hybridizes […]
Intriguing particles emerge when two photons couple
EurekAlert March 2, 2021 An international team of researchers (UK, Russia) has reported a way to create quasiparticles that bind together two differently coloured particles of light. They have named these formations photon-photon polaritons. They tuned a laser to the specific resonance frequency where a photon is expected to be absorbed, yet no resonance absorption happened. Instead, the photon-photon interaction made up two new resonance frequencies away from the old one. The microresonator provided a whole set of split resonances, where each photon-photon pair displayed its own momentum and energy, allowing the researchers to apply the quasiparticle concept and calculate […]