Researchers working in Singapore and the United States have discovered that all entangled states of two particles have a classical 'fingerprint'. This breakthrough could help engineers guard against errors and devices that don't do what they promise in quantum computing and quantum cryptography.
Goh Koon Tong and Valerio Scarani at the Centre for Quantum Technologies at the National University of Singapore, with Andrea Coladangelo at the California Institute of Technology, reported in Nature Communications on 26 May that a simple set of measurements can act as an identity check for any two-particle entangled state. The presence of this fingerprint could help certify quantum computers or quantum encryption devices purchased from third parties.
An entangled quantum state is made of two or more particles held in a multitude of undecided outcomes. Such states are fuel for quantum computing and bring security to quantum communication. The problem is, it is difficult to check that these states have the properties expected of them. That leaves the door open for poorly-functioning devices.
"I like to see our work as bringing the power of testing quantum devices to the consumers who use them. Currently, only those who build the devices or understand the engineering aspect of them can perform the test," says Goh. Quantum physicists could also use this 'self-testing' tool as a check step in lab experiments.
Read more at: https://phys.org/news/2017-05-quantum-states-reveal-fingerprint.html#jCp
Researchers working in Singapore and the United States have discovered that all entangled states of two particles have a classical 'fingerprint'. This breakthrough could help engineers guard against errors and devices that don't do what they promise in quantum computing and quantum cryptography.
Goh Koon Tong and Valerio Scarani at the Centre for Quantum Technologies at the National University of Singapore, with Andrea Coladangelo at the California Institute of Technology, reported in Nature Communications on 26 May that a simple set of measurements can act as an identity check for any two-particle entangled state. The presence of this fingerprint could help certify quantum computers or quantum encryption devices purchased from third parties.
An entangled quantum state is made of two or more particles held in a multitude of undecided outcomes. Such states are fuel for quantum computing and bring security to quantum communication. The problem is, it is difficult to check that these states have the properties expected of them. That leaves the door open for poorly-functioning devices.
"I like to see our work as bringing the power of testing quantum devices to the consumers who use them. Currently, only those who build the devices or understand the engineering aspect of them can perform the test," says Goh. Quantum physicists could also use this 'self-testing' tool as a check step in lab experiments.