Projektbeschreibung
Fehlertolerante Quantennetzwerke
Quantennetzwerke sind ein wichtiges Element des Quantencomputers. Sie ermöglichen die Informationsübertragung in Form von Qubits, indem sie verteilte verschränkte Zustände zwischen physikalisch getrennten Quantenprozessoren weitergeben. Die Quanteninformation ist jedoch sehr fragil. Im Netzwerk verteilte fehlerkorrigierende Qubits können Quanteninformationen vor Fehlern aufgrund von Dekohärenz schützen. Ziel des EU-finanzierten Projekts QUNET ist die Demonstration der Erkennung von Quantenfehlern in einem ein aus vier Knoten bestehenden Quantennetzwerk. Verwirklichte Maßnahmen zur Quantenfehlerkorrektur, mit denen Qubits über große Entfernungen geschützt werden können, wären ein entscheidender Schritt hin zum Aufbau immer größerer Quantennetzwerke.
Ziel
A key question for quantum science is: Can quantum systems be protected from decoherence? This is not just a fundamental question; if we can reliably control large quantum states, it becomes possible to perform precise tests of quantum mechanics and computational tasks that go beyond classical physics.
A promising approach is to protect quantum states by distributing quantum error correction over quantum networks. These networks consist of nodes that contain quantum bits to store and process quantum states, and that are connected by entanglement links based on photons. This approach is naturally scalable to larger sizes by connecting independent modules, and a wide variety of fascinating error correction codes is enabled by different network topologies.
Pioneering experiments have demonstrated basic elements of quantum networks in various systems. However, due to the required precise understanding and control of complex quantum systems, protecting quantum networks against decoherence remains a major outstanding challenge in quantum science.
The goal of this proposal is to demonstrate the detection of quantum errors over a 4-node quantum network. This network forms a unit cell that demonstrates all key principles for larger error-corrected quantum networks. This ambitious goal can now be pursued due to two advances by my colleagues and me using NV centers in diamond: (1) Entanglement of two NV centers through photons and (2) Complete control over multiple nuclear spins coupled to single NV centers. To realize the network, I will develop robust quantum memories, non-destructive spin measurements, and a precise microscopic understanding and control of coupled spin systems in diamond.
Reaching this goal will be a potentially decisive step towards large quantum networks and distributed quantum computations: we will enter a new territory in which quantum states can be made more stable by making networks larger and larger, ultimately completely overcoming decoherence.
Wissenschaftliches Gebiet
- natural sciencesphysical sciencesquantum physics
- natural sciencesmathematicspure mathematicstopology
- engineering and technologyelectrical engineering, electronic engineering, information engineeringinformation engineeringtelecommunicationstelecommunications networks
- natural sciencesphysical sciencestheoretical physicsparticle physicsphotons
Schlüsselbegriffe
Programm/Programme
Thema/Themen
Finanzierungsplan
ERC-STG - Starting GrantGastgebende Einrichtung
2628 CN Delft
Niederlande