Abstract Crystal defects in solid‐state spintronic materials play a crucial role in altering the optical properties of their hosts, enabling widespread applications in the field of quantum information processing. While the majority of the leading platforms are inorganic, they come with limitations such as the challenging material preparations and insufficient amount of active spins. Here, pentacene‐doped p‐terphenyl (Pc:Ptp), an organic spintronic material with easy preparations and tailorable functionalities normally used for microwave quantum electronics, is demonstrated for the first time its ability of self‐cavity laser emission at room temperature. The laser emission is characterized by strong polarization and anisotropy, attributed to the unique packing of the doped molecules (i.e., active spins) within the crystal. The optical coherence is found to be a figure of merit to distinguish the processes of the amplified spontaneous emission (ASE) and lasing in Pc:Ptp. This work highlights the potential of Pc:Ptp as a compact and efficient platform for light‐matter interactions, offering significant promise for enhancing the performance of solid‐state quantum devices based on the organic spintronic material.
Abstract Crystal defects in solid‐state spintronic materials play a crucial role in altering the optical properties of their hosts, enabling widespread applications in the field of quantum information processing. While the majority of the leading platforms are inorganic, they come with limitations such as the challenging material preparations and insufficient amount of active spins. Here, pentacene‐doped p‐terphenyl (Pc:Ptp), an organic spintronic material with easy preparations and tailorable functionalities normally used for microwave quantum electronics, is demonstrated for the first time its ability of self‐cavity laser emission at room temperature. The laser emission is characterized by strong polarization and anisotropy, attributed to the unique packing of the doped molecules (i.e., active spins) within the crystal. The optical coherence is found to be a figure of merit to distinguish the processes of the amplified spontaneous emission (ASE) and lasing in Pc:Ptp. This work highlights the potential of Pc:Ptp as a compact and efficient platform for light‐matter interactions, offering significant promise for enhancing the performance of solid‐state quantum devices based on the organic spintronic material.
Color centers, which are point defects in crystals, play a crucial role in altering the optical properties of their host materials, enabling widespread applications in the field of quantum information processing. While the majority of the state-of-the-art color centers are inorganic, they come with limitations such as the challenging material preparations and insufficient amount of available centers. In contrast, organic color centers have recently gained attention due to their ease of preparations and tailorable functionalities. Here, pentacene-doped p-terphenyl (Pc:Ptp), an organic color-center system normally used for microwave quantum electronics, is demonstrated for the first time its ability of self-cavity laser emission at room temperature. The laser emission is characterized by strong polarization and high anisotropy, attributed to the unique packing of the color-center molecules within the crystal. The optical coherence is found to be a figure of merit to distinguish the processes of the amplified spontaneous emission (ASE) and lasing in Pc:Ptp. This work highlights the potential of Pc:Ptp as a compact and efficient platform for light-matter interactions , offering significant promise for enhancing the performance of solid-state quantum devices based on this organic color-center system.
Molecular room temperature masers have emerged as promising sources of coherent microwaves, but systematic comparisons of organic gain media under uniform conditions remain limited. This paper presents a characterization of two systems, pentacene doped para terphenyl (Pc:PTP, 1.45 GHz) and 6,13 diazapentacene doped para terphenyl (DAP:PTP, 1.478 GHz), examined at four concentrations, including a new 0.05 percent DAP:PTP sample. By evaluating L band masing media under identical conditions, optimal doping levels and gain materials for high power operation are identified. The optimized system produced room temperature continuous wave masing with a peak output of 2.34 mW (+3.69 dBm), marking the first milliwatt level emission from an organic maser. Spectral coherence times of 465 ns and coherence lengths up to 150 m were obtained. Coupling to a high Q cavity mode enables collective spin photon interactions, with Rabi oscillations revealing coherent ensemble dynamics. Frequency domain analysis shows normal mode splitting of 1.37 MHz for Pc:PTP and 2.14 MHz for DAP:PTP, confirming strong coupling. Cavity QED analysis yields cooperativities C* = 304-803 for Pc:PTP and 405-1071 for DAP:PTP, among the highest for organic systems. Quantitative metrics of signal to noise ratio, spectral coherence distance, and throughput demonstrate the potential of these masers for radar, secure communication, and quantum interface technologies.
Through their ability to achieve cryogenic levels of noise performance while operating at room temperature, optically-pumped, solid-state (OPSS) masers show great promise as quantum sensors, oscillators, and amplifiers. We here demonstrate maser oscillation in a microwave cavity containing a crystal of pentacene-doped para-terphenyl (ptc:ptp) pumped by a single, chip-scale LED. Here, unlike previous work, the size of the pump source does not dominate the size of the maser system as a whole. This miniaturization is achieved through invasive optical pumping in the form of a waveguide, the tip of which is embedded into the maser crystal. Using experimental measurements combined with microwave and optical simulations, we find that our approach offers at least a factor-of-2 enhancement in cooperativity over end-on optical excitation. We use our simulations to define a figure of merit for maser pumping efficiency, and conclude that there remains significant headroom to improve the performance of ptc:ptp masers through improved optical design.
Masers can deliver ultralow-noise amplification of microwave signals in medical imaging and deep-space communication, with recent research being rekindled 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.
Coherent sources exploiting the stimulated emission of non-equilibrium quantum systems, i.e. gain media, have proven indispensable for advancing fundamental research and engineering. The operating electromagnetic bands of such coherent sources have been continuously enriched for increasing demands.Nevertheless, for a single bench top coherent source, simultaneous generation of radiation in multiple bands, especially when the bands are widely separated, present formidable challenges with a single gain medium. Here, we propose a mechanism of simultaneously realizing the stimulated emission of radiation in the visible and microwave bands, i.e. lasing and masing actions, at ambient conditions by utilizing photoexcited singlet and triplet states of the pentacene molecules that are doped in p-terphenyl. The possibility is validated by the observed amplified spontaneous emission (ASE) at 645 nm with a narrow linewidth around 1 nm from the pentacene-doped p-terphenyl crystal used for masing at 1.45 GHz and consolidated by a 20 fold lower threshold of ASE compared to the reported masing threshold. The overall threshold of the pentacene-based multiband coherent source can be optimized by appropriate alignment of the pump-light polarization with the pentacene's transition dipole moment. Our work not only shows a great promise on immediate realization of multiband coherent sources but also establishes an intriguing solid-state platform for fundamental research of quantum optics in multiple frequency domains.
Molecular materials that enable coherent control over an electron's spin state at room temperature are promising candidates for quantum technologies, including quantum sensors and ultra-low noise microwave amplifiers, known as masers. Host-guest molecular crystals enable independent control of spin-active guests and their local environments to enhance molecular spin properties and so improve device performance. Using electron paramagnetic resonance and optically-detected magnetic resonance, we demonstrate the ability to tune triplet population, depopulation, and spin-lattice relaxation by modulating host-dependent lattice rigidity and vibrational coupling to significantly reduce the operating requirements for building useful masers. Importantly, the most rigid host, picene, reveals the ability to slow spin-lattice relaxation without lengthening triplet lifetime, though at the cost of strain-induced line width broadening and reduced triplet spin polarisation. We also find that deuteration reduces the triplet resonance line width and vibrationally-mediated triplet depopulation. Consequently, we find that perdeuterated pentacene in perdeuterated p-terphenyl is the most viable candidate for building a continuous wave maser. This work demonstrates host-guest engineering as an important and practical method for tuning the spin-dependent performance of room-temperature molecular quantum technologies.