Most atom-based quantum networks emit photons at non-telecom wavelengths, requiring lossy conversion for long-distance links. A scalable approach for generating direct entanglement between atoms and telecom-band photons has now been demonstrated.
Category: quantum physics – Page 15
Single device amplifies signals while shielding qubits from unwanted noise
Quantum computing, an approach to deriving information that leverages quantum mechanical effects, relies on qubits, quantum units of information that can exist in superpositions of states. To effectively perform quantum computing, engineers and physicists need to be able to measure the state of qubits efficiently.
In quantum computers based on superconducting materials, qubits are indirectly measured by a so-called readout resonator, a circuit that responds differently based on the state of a qubit. This circuit’s responses are probed using a weak electromagnetic wave, which needs to be amplified to enable its detection.
To amplify these signals, also known as microwave tones, quantum technology engineers rely on devices known as amplifiers. Existing amplifiers, however, have notable limitations. Conventional amplifiers can send unwanted noise back to the qubit, disturbing its state. Superconducting parametric amplifiers introduced more recently can be very efficient, but they conventionally rely on bulky and magnetic hardware components that control the direction of signal and protect qubits from backaction noise.
Ultrathin films of ferromagnetic oxide reveal a hidden Hall effect mechanism
Researchers from Japan have discovered a unique Hall effect resulting from deflection of electrons due to “in-plane magnetization” of ferromagnetic oxide films (SrRuO3). Arising from the spontaneous coupling of spin-orbit magnetization within SrRuO3 films, the effect overturns the century-old assumption that only out-of-plane magnetization can trigger the Hall effect.
The study, now published in Advanced Materials, offers a new way to manipulate electron transport with potential applications in advanced sensors, quantum materials, and spintronic technologies.
When an electric current flows through a material in the presence of a magnetic field, its electrons experience a subtle sideways force which deflects their path. This effect of electron deflection is called the Hall effect—a phenomenon that lies at the heart of modern sensors and electronic devices. When this effect results from internal magnetization of the conducting material, it is called “anomalous Hall effect (AHE).”
