Counterfactual Concealed Telecomputation

TL;DR

This paper introduces a novel distributed quantum computation protocol called counterfactual concealed telecomputation (CCT), enabling remote unitary operations without entanglement or particle exchange, using counterfactual techniques and quantum Zeno gates.

Contribution

It presents the first protocol for counterfactual distributed quantum computation that operates without preshared entanglement and physical particle exchange, with a simplified deterministic implementation.

Findings

Protocol is valid for general input states.

Single-qubit unitary teleportation is a special case of CCT.

Deterministic implementation possible with Bell-type initial states.

Abstract

Distributed computing is a fastest growing field -- enabling virtual computing, parallel computing, and distributed storage. By exploiting the counterfactual techniques, we devise a distributed blind quantum computation protocol to perform a universal two-qubit controlled unitary operation for any input state without using preshared entanglement and without exchanging physical particles between remote parties. This distributed protocol allows Bob to counterfactully apply an arbitrary unitary operator to Alice's qubit in probabilistic fashion, without revealing the operator to her, using a control qubit -- called the counterfactual concealed telecomputation (CCT). It is shown that the protocol is valid for general input states and that single-qubit unitary teleportation is a special case of CCT. The quantum circuit for CCT can be implemented using the (chained) quantum Zeno gates and the protocol becomes deterministic with simplified circuit implementation if the initial composite state of Alice and Bob is a Bell-type state.