A note on superposition of two unknown states using Deutsch CTC model

TL;DR

This paper demonstrates that the presence of closed time-like curves allows for creating superpositions of unknown quantum states, bypassing previous no-go theorems that forbade such superpositions in standard quantum mechanics.

Contribution

It introduces a novel scenario where closed time-like curves enable superposition of unknown states, challenging existing no-go theorems in quantum information.

Findings

Superposition of unknown states is possible with closed time-like curves.

The no-go theorem does not hold in the presence of closed time-like curves.

Closed time-like curves enable new quantum information processing possibilities.

Abstract

In a recent work, authors prove a yet another no-go theorem that forbids the existence of a universal probabilistic quantum protocol producing a superposition of two unknown quantum states. In this short note, we show that in the presence of closed time like curves, one can indeed create superposition of unknown quantum states and evade the no-go result.