Resource-efficient coherent optical frequency transfer for distributed quantum computing and the quantum internet of things
A unified quantum network architecture is introduced that seamlessly applies to all memory types while sharply reducing experimental overhead. The scheme depends on the following elements: A unified quantum network framework based on photon heralding. As a unified quantum network framework, a scheme for optically heralded entanglement that applies to superconductor-to-optical interfaces equally as to other memory-photon interfaces (such as spin-photon interfaces, and others). To address the challenges noted above, a scheme termed “Universal Quantum Bus” (UQB) is introduced. UQB is described for connecting diamond color centers across a telecom fiber network, however the scheme works equally for all other memory types.
1 . A quantum network, comprising: a plurality of nodes, wherein each node j comprises a plurality (k) of quantum memories, wherein each node j utilizes an oscillator output to drive quantum memory transitions at frequencies ω j,k , wherein the plurality of nodes are connected across a telecom fiber network; a quantum bus channel that allows a master laser output at frequency ω o to be distributed across the quantum network; and a non-linear crystal to couple the output at frequency ω o and the oscillator outputs at frequencies ω j,k .
2 . The quantum network of claim 1 , wherein the quantum memories comprise a modality selected from the group consisting of atoms, microwaves in superconductors, ions, and solid state spins.
3 . The quantum network of claim 1 , wherein the node j uses a local oscillator to generate ω c,k , which is used to produce an electromagnetic field ω j,k =ω c,k +ω 0 by sum-frequency generation.
4 . The quantum network of claim 3 , wherein the node j locally generates ω c,k =ω c,0 +Δω c,k where Δω c,k is dynamically adjusted to tune from a local laser oscillator at ω c,0 to ω c,k .
5 . The quantum network of claim 3 , wherein the node j interacts the quantum memory at frequency ω j,k with the electromagnetic field produced by sum-frequency generation at ω j,k .
6 . The quantum network of 1 , wherein the node j uses a local oscillator to generate ω c,k −j QITU Δω oQITU , which is used to produce an electromagnetic field ω 0 +j QITU Δω oQITU from ω j,k by difference-frequency generation.
7 . The quantum network of claim 6 , wherein the electromagnetic field ω 0 +j QITU Δω oQITU is a different quantum bus channel.
8 . The quantum network of claim 1 , wherein the node j comprises a local oscillator to generate ω c,0 , a first modulator to generate ω c,k =ω c,0 +Δω c,k , a second modulator to generate ω c,k −j QITU Δω oQITU , a sum-frequency generator to create ω j,k =ω c,k +ω 0 , and a difference-frequency generator to create ω 0 +j QITU Δω oQITU .
9 . The quantum network of claim 8 , wherein the first modulator and the second modulator are one component that is used in a time multiplexed manner.