Electricity Reads Out Diamond Spins ⚡ экспресс
For spin qubits in diamond, electrical readout is attractive due to its chip-level scalability, yet it has lagged behind optical methods in accuracy. The CCDMR protocol is proposed: the spin information of an NV center is converted into charge carriers, which are then trapped for a long time at the metal–diamond interface (Schottky barrier). Subsequent illumination and voltage release the charge, producing a photocurrent proportional to the initial spin. The method has been successfully tested after coherent control of single NV centers, combining the benefits of electrical detection with the stability of long-lived traps in wide-bandgap materials.
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.