HomePhysicsQuantum Steering That’s Sturdy to Loss and Noise

Quantum Steering That’s Sturdy to Loss and Noise

• Physics 15, s168

Researchers display a loss-tolerant technique for so-called quantum steering, a phenomenon that would give quantum communication networks full safety.

V. Srivastav/Heriot-Watt College

Quantum methods are weird. One lesser-known quirky quantum habits is the entanglement phenomenon generally known as quantum steering. Like different entanglement phenomena, quantum steering is definitely destroyed by noise, limiting its use in purposes. Now Mehul Malik of Heriot-Watt College, UK, and his colleagues display noise-robust, loss-tolerant quantum steering, growing its technological potential [1].

When two events—Alice and Bob—share a pair of particles in a strongly correlated entangled state, any measurements made on the particles are linked such that measurements made by Alice can be utilized to foretell the result of measurements made by Bob. In quantum steering, this correlation goes a step additional: by making sure measurements on her particle, Alice can “steer” the quantum state of Bob’s particle to tackle a particular kind.

Quantum steering can be utilized as a verification step to indicate {that a} line between Alice and Bob stays safe, even when Alice doesn’t belief her gadgets or the channel in between. It has extra relaxed necessities than different device-independent verification strategies, making it attention-grabbing for future communication networks. However quantum steering has the identical noise and information-loss issues. To date, strategies that try to beat these issues have required impractically giant numbers of measurements.

The protocol developed by Malik and colleagues makes use of photon pairs which have “high-dimensional” entanglement—they are often entangled in 53 dimensions quite than the conventional two. This high-dimensional entanglement makes the quantum correlations between the photons stronger, which reduces the susceptibility of the system to noise. The staff efficiently used their protocol to steer entangled photons by means of the equal of 79 km of telecommunication fiber. Malik says that “having a loss-tolerant technique for steering entanglement opens a pathway towards sensible quantum communication networks with the last word safety.”

–Katherine Wright

Katherine Wright is the Deputy Editor of Physics Journal.


  1. V. Srivastav et al., “Fast quantum steering: Overcoming loss and noise with qudits,” Phys. Rev. X 12, 041023 (2022).

Topic Areas

Quantum PhysicsQuantum Info

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