quality-factor (Q) microwave resonator magnetically loaded with optically pumped pentacene doped in para-terphenyl (Pc:PTP) provides one route toward this goal, [1] and diamond with negatively charged nitrogen-vacancy defects (NV − diamond) has also been considered. [2] However, attaining a sufficiently high spin polarization density for strong coupling from other materials has, at room-temperature, proven elusive.Room-temperature masers (microwave amplification by stimulated emission of radiation) can be made out of either Pc:PTP or NV − diamond, [4,5] but Pc:PTP remains the sole material able to mase without any externally applied magnetic field (zero-field) at room-temperature. Unfortunately, it has a drawback in that it suffers from lag (of several microseconds) at start up; when operating in pulsed mode (e.g., providing low-noise amplification solely when required) this lag excludes applications that require a rapid response. Since masers on the benchtop remain as tantalizing prospects for achieving ultralow-noise amplification applicable to MRI in medical devices, deep space communication and for demonstrating cQED at room-temperature, [1] the discovery of other maser materials could help accelerate developments in these fields. Masers can deliver ultralow-noise amplification of microwave signals in medical imaging and deep-space communication, with recent research beingrekindled through the discovery of gain media operating at room-temperature, eschewing bulky cryogenics that hindered their use. This work shows the discovery of 6,13-diazapentacene doped in para-terphenyl (DAP:PTP) as a maser gain medium that can operate at room-temperature, without an external magnetic field. With a maser output power of −10 dBm, it is on par with pentacene-doped para-terphenyl in masing power, while possessing compelling advantages such as faster amplification startup times, being pumped by longer wavelength light at 620 nm and greater chemical stability from nitrogen groups. Furthermore, the maser bursts from DAP:PTP allow one to reach the strong coupling regime for cavity quantum electrodynamics, with a high cooperativity of 182. The optical and microwave spin dynamics of DAP:PTP are studied in order to evaluate its capabilities as a maser gain medium, where it features fast intersystem crossing and an advantageously higher triplet quantum yield. The results pave the way for the future discovery of similar maser materials and help designate them as promising candidates for quantum sensors, optoelectronic devices and the study of cavity quantum electrodynamic effects at room-temperature.

The development of future quantum devices such as the maser, i.e., the microwave analog the laser, could be well-served by exploration of chemically tuneable organic materials. Current iterations of room temperature organic solid-state masers are composed of an inert host material that is doped with a spin-active molecule. In this work, we have systematically modulated the structure of three nitrogen-substituted tetracene derivatives to augment their photoexcited spin dynamics and then evaluated their potential as novel maser gain media. To facilitate these investigations, we adopted an organic glass former, 1,3,5-tri(1-naphthyl)benzene (1-TNB) to act a universal host. These chemical modifications impacted the rates of intersystem crossing, triplet spin polarisation, triplet decay and spin-lattice relaxation, leading to significant consequences on the conditions required to surpass the maser threshold.

The development of future quantum devices such as the maser, i.e., the microwave analog the laser, could be well-served by exploration of chemically tuneable organic materials. Current iterations of room temperature organic solid-state masers are composed of an inert host material that is doped with a spin-active molecule. In this work, we have systematically modulated the structure of three nitrogen-substituted tetracene derivatives to augment their photoexcited spin dynamics and then evaluated their potential as novel maser gain media. To facilitate these investigations, we adopted an organic glass former, 1,3,5-tri(1-naphthyl)benzene (1-TNB) to act a universal host. These chemical modifications impacted the rates of intersystem crossing, triplet spin polarisation, triplet decay and spin-lattice relaxation, leading to significant consequences on the conditions required to surpass the maser threshold.

A method for simulating coupled electromagnetic and mechanical vibrations on arbitrarily shaped piezoelectric structures is presented. This method is based on weak forms and can be implemented in any finite-element-method software, allowing editable access to their definitions. No quasi-static approximation is imposed, meaning that magnetic fields generated by displacement currents within piezoelectric materials are captured, enabling the flow of electromagnetic energy inside and around structures containing such material to be accurately simulated. The method is particularly relevant to the design of piezoelectric antennas, resonators, and waveguides exploiting either bulk or surface-acoustic waves. The accuracy and capabilities of the method are demonstrated by simulating, in COMSOL Multiphysics, (i) a Rayleigh mode on the surface of Z-cut lithium niobate crystal and (ii) a torsional mode of a cylinder of lead zirconium titanate (PZT-5H) ceramic functioning as a micro-antenna.

The development of future quantum devices such as the maser, i.e., the microwave analog of the laser, could be well-served by the exploration of chemically tunable organic materials. Current iterations of room-temperature organic solid-state masers are composed of an inert host material that is doped with a spin-active molecule. In this work, we systematically modulated the structure of three nitrogen-substituted tetracene derivatives to augment their photoexcited spin dynamics and then evaluated their potential as novel maser gain media by optical, computational, and electronic paramagnetic resonance (EPR) spectroscopy. To facilitate these investigations, we adopted an organic glass former, 1,3,5-tri(1naphthyl)benzene to act as a universal host. These chemical modifications impacted the rates of intersystem crossing, triplet spin polarization, triplet decay, and spin−lattice relaxation, leading to significant consequences on the conditions required to surpass the maser threshold.