Welcome to the Quantum Realm.

Enjoy today’s breakdown of news, research, & events within quantum.

⚡️ An ode to photons — photonic computers for space, NASA’s first quantum memory releases information as photons, silicon carbide-on-insulator can integrate photonic devices, photons absorbed by quantum dots destroy PFAs, and MBQC/FBQC methods for scalable fault-tolerant architecture. May this issue light up your day (plus, it’s Friday).

🗓️UPCOMING

Saturday, August 3rd | Optimizing Complex Processes using AI and QC

Tuesday, August 6th | Yale Ventures Startup Speaker Series: Mark Jackson, Quantinuum

Tuesday, August 6th | QED-C Summer Lecture Series: Inertial Sensors

📰QUANTUM QUICK BYTES

🖥️ Building PhoQuant’s photonic quantum computer for advanced computations: A German collaboration, PhoQuant, is creating a photonic quantum computer using photonic integrated circuits for scalability, backed by €50 million. Current efforts are focused on system architecture, operability, and integration to operate at room temperature. The project involves a hybrid platform for component miniaturization and integration, with plans to upgrade the photonic integrated chip from 4-mode to 100-mode interferometers. Future developments anticipate photonic quantum computers as part of a broader computing ecosystem to address complex, specific problems.

🌌 NASA and Infleqtion Inc. develop NASA's first quantum memory: NASA’s Glenn Research Center and Infleqtion Inc. have developed NASA’s first quantum memory, storing information in a cloud of laser-cooled atoms. This is part of NASA's efforts to create large-scale quantum networks for secure space communications and scientific discoveries. Quantum memory stores information encoded in matter or photons for a certain time and then releases it as photons. Current quantum networks rely on fiber optics, which limits distance due to information degradation. Quantum memory in space could enable long-distance information transmission via free space transmission. The research team will continue to refine this technology and use simulations to assess its potential in large-scale networks.

💾 Silicon carbide-on-insulator promising for scalable spin-photon interfaces and CMOS compatibility: Silicon carbide-on-insulator is an emerging platform for quantum information transmission using single photons. It offers long spin coherence, CMOS compatibility, and favorable material properties making it a superior host for quantum phenomena. SiCOI can also integrate photonic devices such as waveguides and photonic crystal cavities which contribute to improved quantum operations and information distribution. Challenges include achieving high-fidelity multi-qubit control and photon-mediated entanglement on-chip. Future applications may include quantum memories, quantum communication, and scalable quantum processors.

🚀 Rotonium to develop room-temperature photonic quantum computers for space: Rotonium has raised a €1 million seed investment to advance its quantum computing research in developing and testing photonic components for a new single-photon qubit-based quantum processor. This technology allows quantum computers to operate at room temperature, which is ideal for miniaturization and applications in extreme environments, including space.

☀️ Quantum dots can destroy PFAS using visible light: Researchers at Ritsumeikan University in Japan have discovered that visible light shining through quantum dots can break down "forever chemicals" such as PFAS. These chemicals, known for their durability and harmful health effects, typically require extreme methods for destruction. The team used cadmium sulphide and copper quantum dots, which absorb specific light wavelengths to break strong carbon-fluorine bonds in PFAS. In experiments, they successfully degraded PFOS entirely within 8 hours and 80% of Nafion within 24 hours. Though their experiments used simple LED lights at room temperature and pressure, practical application on a larger scale remains uncertain.

🌐 Tamil Nadu launches quantum computing education for all technical degree programs using Q-CTRL's Black Opal: Aravind Ratnam, Chief Strategy & Revenue Officer at Q-CTRL, announced on LinkedIn that Tamil Nadu has become the first state to introduce quantum computing education across all technical degree programs through the Naan Mudhalvan scheme. This initiative will up-skill hundreds of thousands of students using Q-CTRL's Black Opal software. Supported by TNSDC's leadership and Austrade, this goal is to expand this program across India and abroad to create a new generation of quantum developers.

☕️FRESHLY BREWED RESEARCH

HIGH-PHOTON-LOSS THRESHOLD QUANTUM COMPUTING USING GHZ-STATE MEASUREMENTS

AND

ENCODED-FUSION-BASED QUANTUM COMPUTATION FOR HIGH THRESHOLDS WITH LINEAR OPTICS

QUICK BYTE: The inherent low decoherence rates of photonic qubits and the scalability of linear optical elements make photonic quantum computing an appealing modality for fault-tolerant quantum computation. Recent developments towards fault-tolerant architecture include measurement-based quantum computation using GHZ-state measurements and fusion-based quantum computation with encoded fusion operations, which significantly improve photon-loss thresholds toward building scalable quantum computers.

SIGNIFICANCE: The fragility of quantum systems in the presence of noise requires advanced error correction to move towards fault-tolerant quantum computation. Quantum error correction codes provide continuous protection so quantum computations may proceed reliably. By maintaining the error rate below a critical threshold, quantum computers will be able to scale up and perform complex and long-running computations without being overwhelmed by errors.

Photonics are highly suitable for fault-tolerant quantum computation due to their low decoherence rates, high-speed operations, room temperature functionality, and scalability. Additionally, the integration of quantum computation and quantum communication increases the potential of photonic systems for creating scalable and distributed quantum computing architectures.

Measurement-based quantum computation and fusion-based quantum computation are two methods that can be used in photonic quantum computing. In MBQC, computation progresses through a sequence of measurements on a highly entangled initial state, gradually consuming this state (one-way quantum computing). MBQC is particularly effective with photonics due to easy entanglement and measurement of photons. In High-Photon-Loss Threshold Quantum Computing Using GHZ-State Measurements, researchers designed linear-optical architectures that use encoded GHZ-state measurements to fuse constant-sized entangled resource states. Their numerical simulations demonstrated significantly improved photon-loss thresholds compared to other linear-optical architectures.

Fusion-based quantum computation, on the other hand, uses the fusion of entangled photon pairs to perform quantum operations, measuring pairs or groups of qubits to achieve fusion. In Encoded-Fusion-Based Quantum Computation for High Thresholds with Linear Optics, researchers implemented encoded fusion-based quantum computation by using finite-sized entangled resource states and applying encoded fusion operations based on quantum error-correcting codes like the generalized Shor code, improving fusion success probabilities under photon loss.

RESULTS: 

MBQC: 

• Reaches photon-loss thresholds up to 12%

• Achieves high thresholds with modest-sized resource states, practical with current photonic devices

• Effectively suppresses errors due to photon loss and the probabilistic nature of linear optics

FBQC 

• Reaches photon-loss thresholds up to 14%

• Uses fewer photons and a two-step linear-optical process, improving fusion success and minimizing photon loss

• Compatible with various architectures and resource states

HONORABLE RESEARCH MENTIONS:

A method using optimally designed shortcuts to adiabaticity achieves nearly perfect population inversion in cat-state qubits. Numerical simulations show high insensitivity to systematic errors, maintaining over 99% population in the target state even with a 20% parameter imperfection rate. —> link to Optimally robust shortcuts to population inversion in cat-state qubits

An integrated photon-pair source uses a silicon carbide micro-ring resonator for quantum memory in the telecom band. It optimizes waveguide dimensions to generate photons at specific wavelengths, matching the properties needed for interaction with erbium-doped crystals. The device shows promise for scalable quantum communication networks. —> link to Integrated photon pairs source in silicon carbide based on micro-ring resonators for quantum storage at telecom wavelengths

Successful demonstration of teleportation across a quantum network is done using measurement-based quantum network coding on superconducting processors. MQNC was adapted to modern hardware, achieving higher fidelity teleportation than classical methods by focusing on a specific subset of quantum states. This work provides valuable techniques for practical quantum communication and future improvements in quantum networks. —> link to Demonstration of teleportation across a quantum network code

UNTIL TOMORROW.