Electricity Reads Out Diamond Spins ⚡ экспресс
Electrical readout of solid-state spins is scalable and not limited by photon budget, but in wide-bandgap materials its accuracy and speed lagged behind optical methods. A photoelectric approach is proposed: spin-dependent photoionization of NV centers in diamond generates charge carriers, which are captured by long-lived traps at the metal-diamond Schottky barrier. Subsequent illumination and electric bias release the accumulated charge, creating a photocurrent proportional to the initial spin. With single NV centers after coherent control, the CCDMR (charge-capture detected magnetic resonance) protocol has been demonstrated. Additionally, charge imaging was used to investigate carrier generation and trapping. CCDMR combines the advantages of electrical detection with the stability of deep traps, opening a new path for spin-qubit readout in wide-bandgap semiconductors.
Quantum computers demand reliable memory. In a diamond crystal — carbon — information is stored as the orientation of microscopic magnetic needles (spins) at special defects. Reading these arrows with light was inconvenient: optics are bulky for chips. The new method works like developing photographic film.
First, the laser “exposes” the spin: if the arrow points one way, the defect ejects an electron into a microscopic trap at the diamond’s edge; if the other way, it doesn’t. The charge can sit there for hours. Then, by applying voltage and shining light again, the traps are shaken — and the collected electrons create a current pulse. The magnitude of this photocurrent reveals the original spin direction. The method, called CCDMR (magnetic resonance with charge capture), is entirely electrical: no need to catch faint flashes. It can be easily placed on a crystal, creating quantum chips the size of a fingernail.
🎯 Electron traps in diamond are so stable that the charge stored in them can last for years — far longer than most laboratory instruments operate.
🎬 The idea of storing information in crystals is familiar from Superman: his Fortress of Solitude used crystals as a database. Diamond quantum chips are almost the same thing, only in reality.