Spin Entanglement Witness for Quantum Gravity

Understanding gravity in the framework of quantum mechanics is one of the great challenges in modern physics. However, the lack of empirical evidence has lead to a debate on whether gravity is a quantum entity. Despite varied proposed probes for quantum gravity, it is fair to say that there are no feasible ideas yet to test its quantum coherent behavior directly in a laboratory experiment. Here, we introduce an idea for such a test based on the principle that two objects cannot be entangled without a quantum mediator. We show that despite the weakness of gravity, the phase evolution induced by the gravitational interaction of two micron size test masses in adjacent matter-wave interferometers can detectably…

• NS
  National Science Foundation

  Awards: PHY-1506431, 1506431
• FQ
  Foundational Questions Institute
• LT
  Leverhulme Trust

  Awards: RPG-2016-046, RPG-2014-055
• RS
  Royal Society
• EC
  European Cooperation in Science and Technology

  Award: CA15220
• SF
  Science Foundation Ireland

  Awards: 15/IA/2864, 15/IA/
• EA
  Engineering and Physical Sciences Research Council

  Awards: M013243/1, EP/M013243/1, EP/K034480, EP/N031105, EP/N031105/1, EP/K034480/1, K034480/1, EP/K004077/1, EP/N031105/1, EP/K034480/1, EP/K004077/1, EP/M013243/1, EP/K004077
• HE
  H2020 European Research Council

  Award: 308253