Mentor-Initiated Asymmetric Bidirectional Quantum Teleportation Protocol for Arbitrary Qubit States

arXiv:2610.01684 · quant-ph · Submitted 2026-10-01 · Read on arXiv

Listen

Radio episode about this paper

Transcript

Introduction to the show: ident: Quantum Radio. Generated commentary on the latest quantum physics and condensed matter papers.

Kai: Today's paper: "Mentor-Initiated Asymmetric Bidirectional Quantum Teleportation Protocol for Arbitrary Qubit States".

Mira: The gist The proposed work introduces a mentor-initiated bidirectional asymmetric quantum teleportation protocol that enables the transfer of an arbitrary one-qubit state from Alice to Bob and an arbitrary two-qubit…

Kai: First, who's behind it and why it matters.

Title and authors: Kai: So we're looking at this paper called "Mentor-Initiated Asymmetric Bidirectional Quantum Teleportation Protocol for Arbitrary Qubit States." It sounds like a pretty complex setup, and the authors are suggesting something that goes beyond the usual restrictions on what states can be sent back and forth.

Mira: Exactly. The title hints at a bidirectional protocol that handles arbitrary states, which is significant because most existing mentor-initiated schemes are limited to specific Bell-like states eleven <ref:2610.01684#pg1>. This paper is aiming to expand that reach.

Lev: It's interesting because the goal isn't just transferring some known quantum states but allowing for completely arbitrary one-qubit and two-qubit states between Alice and Bob. That broad applicability is what makes it noteworthy in error correction research, as you have to deal with a wider variety of input conditions.

Kai: Right, so instead of being restricted to those specific Bell forms that previous mentor protocols used, this new protocol lets Alice send any arbitrary one-qubit state and Bob send any arbitrary two-qubit state back.

Mira: And they do this without needing any prior entanglement between Alice and Bob directly; the mentor handles building the necessary entangled channels first. That's a key structural difference we need to keep in mind, especially when thinking about how hardware might actually implement this.

Lev: It means the complexity of setting up the initial resources is shifted entirely to the mentor, leaving Alice and Bob with a standard teleportation process once that setup is done. We need to see if those resource constructions are feasible on real quantum chips.

The paper's summary: Kai: The summary explains that the protocol involves a mentor initiating everything by creating two entangled channels, omega1⟩M−A and omega2⟩M−B, which connect the mentor to Alice and Bob separately <ref:2610.01684#pg1>. Then, the mentor performs Bell-basis measurements on pairs like (m1, m4), (m2, m5), and (m3, m6).

Mira: The core idea is that these measurements collapse the remaining qubits into sixty-four possible conditional states <ref:2610.01684#pg3>. But here's where it gets interesting: Alice does a Bell-basis measurement on her pair to get information from Bob, and Bob does similar measurements to recover his two-qubit state back at Alice’s end.

Lev: So, the protocol relies on classical communication between the mentor and both Alice and Bob telling them which measurements they made so they can perform the correct final operations. That reliance on classical communication is something we need to be careful about when thinking about network latency and security.

Kai: The authors quantify their efficiency by eta = q t/q c + b t, which they report as twelve point five percent. They justify this because the protocol works for all arbitrary two-qubit states, unlike previous schemes that were restricted to specific Bell-like states eleven <ref:2610.01684#pg1>.

Mira: That efficiency figure is interesting, especially when you consider the complexity of the resource construction involving Hadamard, CNOT, and SWAP gates used to build those entangled channels. We have to assume those gate operations are implemented accurately for this efficiency number to hold true in practice.

Lev: From an error correction standpoint, a twelve point five percent efficiency suggests there is still room for improvement in terms of fidelity if we were trying to run this on noisy hardware, but it proves the conceptual framework works for arbitrary states.

The paper's improvements: Kai: The main improvement they highlight is that this protocol overcomes the limitation where previous mentor-initiated protocols were restricted to specific Bell-like states. This new version achieves universal applicability for two-qubit states, allowing for all combinations of alpha, beta, gamma, and delta in Bob's transmitted state.

Mira: That universality is what makes it powerful; it means we aren't stuck dealing with a small subset of possible quantum information being transferable. They are also showing how to achieve this by constructing the required entangled resources using standard gates like Hadamard, CNOT, and SWAP gates rather than some exotic new operations.

Lev: From an error correction perspective, if you were trying to implement this on actual hardware, the resource construction must be robust against gate errors because any mistake in those initial CNOTs or SWAPs would propagate through the entire state collapse process.

Kai: The structure itself is also noted as being operationally straightforward. It relies on standard bipartite Bell-basis measurements and avoids needing complex multi-qubit joint measurements, which simplifies the physical realization of the protocol.

Mira: That simplicity in terms of measurement types is a big plus, but we have to look at the overhead introduced by the mentor's role—the two separate entangled channels and all those initial gate operations needed to build them. We need to figure out if that overhead is worth the flexibility they gain.

Lev: If we think about scaling this up for a network, avoiding complex joint measurements simplifies things immensely because you don't need massive quantum registers just to perform one step of the teleportation process.

Conclusion: Kai: To wrap up, this paper on the "Mentor-Initiated Asymmetric Bidirectional Quantum Teleportation Protocol for Arbitrary Qubit States" shows we can achieve simultaneous transfer of an arbitrary one-qubit state from Alice to Bob and an arbitrary two-qubit state from Bob to Alice.

Mira: The main implication is the move away from being stuck with specific Bell states, allowing for truly universal quantum information exchange between parties using a mentor setup. It establishes a clearer path for how we can use mentors to establish communication channels without directly sharing the final required entangled resource between the sender and receiver.

Lev: For error correction, this protocol gives us a concrete model of how to manage state transfer when the initial entanglement is mediated by an intermediary like the mentor, which is useful for designing better error mitigation strategies.

Kai: So, while it’s not perfect—remember that twelve point five percent efficiency number—the paper shows a working blueprint for achieving this bidirectional capability with arbitrary states. It's a solid piece of work on the theory and circuit design side.

Mira: Yeah, the focus now should be on those future work items mentioned by the authors, like integrating controllers to supervise the exchange process for better security in quantum networks. That’s where the practical engineering challenge lies next.

Lev: I agree with Mira; controlling that bidirectional flow will be essential if we want to move this from a theoretical concept onto a stable, secure network implementation.

Kai: Alright then, we've covered the proposal for this protocol and where it stands now. We'll keep an eye out for whatever comes next in the quantum community.

Bhawanipur Education Society College, Kolkata, India · Information Engineering University, Zhengzhou, China

quant-ph

Submitted: 2026-10-01

Updated: 2026-10-08

Comments: 9 pages, 4 figures, Simulation Added

License: http://creativecommons.org/licenses/by/4.0/

Importance score: 76/100

The gist: The gist The proposed work introduces a mentor-initiated bidirectional asymmetric quantum teleportation protocol that enables the transfer of an arbitrary one-qubit state from Alice to Bob and an

Key concepts

Mentor-Initiated Protocol
In this scheme, a mentor acts as a central party who initiates the process by creating the necessary entanglement channels between Alice and Bob. Once the mentor establishes these links, the actual quantum teleportation can proceed between Alice and Bob without further intervention from the mentor.
Bidirectional Teleportation
This refers to a system where quantum information can be transferred simultaneously in both directions: from one party to another (e.g., Alice to Bob) and back from the second party to the first (e.g., Bob to Alice). This allows for a continuous exchange of quantum states between the two parties.
Arbitrary State Transfer
The protocol is designed so that Alice can send any arbitrary one-qubit state, and Bob can send any arbitrary two-qubit state. This universality is a key improvement over prior methods that were limited to transferring only specific types of entangled states or restricted states.
Entangled Resource Construction
The required quantum entanglement channels are not directly shared between Alice and Bob initially. Instead, they are constructed using standard quantum gates like Hadamard, CNOT, and SWAP operations on a set of initial qubits to create the necessary resources for the teleportation process.

Terminology

Summary

The gist The proposed work introduces a mentor-initiated bidirectional asymmetric quantum teleportation protocol that enables the transfer of an arbitrary one-qubit state from Alice to Bob and an arbitrary two-qubit state from Bob to Alice, overcoming limitations in existing schemes that restrict transmitted states

Proposed Protocol Overview

The protocol allows Alice to transmit an arbitrary one-qubit state ψ1⟩a1 = x0⟩ + y1⟩ and Bob to transmit an arbitrary two-qubit state ψ2⟩b1b2 = α00⟩ + β01⟩ + γ10⟩ + δ11⟩ Initially, Alice and Bob do not share any entangled quantum channel between them, but a mentor is connected to both through two different entangled channels. The protocol utilizes two entangled quantum resources omega1⟩M−A shared between mentor and Alice, and omega2⟩M−B shared between mentor and Bob.

Entangled Resource Construction

The required entangled resources are constructed using standard quantum gates, specifically Hadamard, CNOT, and SWAP gates. The six-qubit input state S0 is transformed by applying Hadamard gates on q[0], q[1], q[2] to reach S1. The first entangled channel omega1⟩M−A is obtained by applying CNOT gates to the qubit pairs (q[0], q[5]), (q[1], q[4]), and (q[2], q[3]) on S1. The second entangled channel omega2⟩M−B is obtained if a SWAP gate is applied to the qubit pair (q[0], q[2]) on omega1⟩M−A.

Mentor-Initiated Teleportation Steps

The mentor initiates the protocol by performing Bell-basis measurements simultaneously on the qubit pairs (m1, m4), (m2, m5), and (m3, m6). The four maximally entangled two-qubit Bell states are defined as ϕ±⟩ = 1/√200⟩ ± 11⟩ and ψ±⟩ = 1/√201⟩ ± 10⟩. The mentor communicates the outcomes of the Bell-basis measurements (m1, m4) and (m2, m5) to Alice and (m3, m6) to Bob through classical communication channels. Following these measurements, the composite state of the remaining qubits collapses into one of 64 possible conditional states ξαβγ⟩A1A2A3B1B2B3.

State Recovery and Efficiency Analysis

Alice performs a Bell-basis measurement on the qubit pair (a1, A1) and communicates her outcome to Bob. Simultaneously, Bob performs Bell-basis measurements on the qubit pairs (b1, B1) and (b2, B2) and communicates his outcomes to Alice. Based on this information, Bob performs suitable unitary operation on qubit B3 to deterministically recover the state ψ1⟩. Similarly, Alice performs suitable unitary operation on her qubits (A2, A3) to deterministically recover the state ψ2⟩ at her end. The efficiency of the protocol is quantified by η = qt/qc + bt, which yields a value of 12.5%. This efficiency is justified because the protocol is designed to be universally applicable for all arbitrary two-qubit states, unlike previous schemes restricted to specific Bell-like states.

Conclusion and Future Work

The key advantage of this scheme is its universal applicability to arbitrary two-qubit states, whereas recent mentor-based protocols are restricted to specific Bell-like states. The protocol is operationally straightforward, relying exclusively on standard bipartite Bell-basis measurements and completely avoiding the need for complex multi-qubit joint measurements. Future research should focus on integrating one or more controllers to supervise the bidirectional state exchange process for enhanced security in quantum networks. The paper concludes that this mentor-initiated asymmetric bidirectional quantum teleportation protocol successfully achieves the simultaneous exchange of an arbitrary single-qubit state from Alice to Bob and an arbitrary two-qubit state from Bob to Alice.

--- Page 1 ---

Mentor-Initiated Asymmetric Bidirectional Quantum Teleportation Protocol for Arbitrary Qubit States

Sugata Adhya∗1 and Benchao Yang †2

1The Bhawanipur Education Society College, Kolkata, India

2Information Engineering University, Zhengzhou, China

Abstract

In this paper, a mentor-initiated bidirectional asymmetric quantum teleportation protocol is proposed

Keywords: Mentor; bidirectional protocol; quantum teleportation.

1 Introduction

Quantum teleportation enables the transfer of quantum information by exploiting the property of quantum entanglement, providing a powerful framework for high-capacity and secure quantum communication compared with classical communication. The process utilizes shared entangled resources and classical communication to transfer an unknown quantum state from a sender to a receiver without physically transmitting the state itself. In 1993, Bennett et al. [2] first proposed a quantum teleportation protocol employing an Einstein–Podolsky–Rosen (EPR) entangled pair as the quantum resource for transferring an unknown quantum state between two parties. This pioneering result opened up possibilities for the development of numerous quantum protocols for different forms of quantum teleportation, significantly advancing the field of quantum communication. Among the various schemes for enhanced quantum teleportation, bidirectional quantum teleportation protocols provide a framework for the simultaneous exchange of quantum information between two parties. Bidirectional teleportation was subsequently investigated in different forms, including asymmetric protocols in which the numbers of qubits transmitted in the two directions are different. Following these developments, several bidirectional quantum teleportation protocols have been proposed using different entangled quantum resources and communication schemes. For example, interested readers may consult [1, 6, 8, 11, 13, 14, 15, 16] and the references therein.

Within the class of bidirectional teleportation schemes, mentor-initiated protocols provide an additional mechanism for controlling the establishment of the quantum channel. In a mentorinitiated scheme, the mentor is a party who initiates the protocol by participating in the creation of the entangled channel between the sender and receiver. Initially, the sender and receiver do not directly share the required entangled channel; rather, the mentor participates in establishing the entanglement needed for subsequent quantum communication. Once the entangled channel has been established, the mentor’s role in the protocol is completed, allowing the sender and receiver to perform quantum teleportation through the established channel. Mentor-initiated schemes have subsequently been investigated in various forms, including remote state preparation, bidirectional controlled teleportation, and bidirectional asymmetric teleportation [3, 4, 5, 6, 9, 11].

In particular, the authors of [11] proposed a mentor-initiated controlled bidirectional asymmetric quantum teleportation protocol in which Alice teleports an arbitrary one-qubit state to Bob, whereas Bob teleports a two-qubit Bell-like state of the form α00⟩ + β11⟩ to Alice. The protocol is initiated by a mentor and operates in the presence of controllers. However, their scheme is not applicable to the teleportation of an arbitrary two-qubit state from Bob to Alice. In our work, we address this limitation by proposing a mentor-initiated bidirectional asymmetric quantum teleportation protocol that enables the teleportation of an arbitrary one-qubit state from Alice to Bob and an arbitrary two-qubit state from Bob to Alice. We construct the required entangled resources and demonstrate the proposed protocol through its quantum-circuit implementation.

This paper is organized as follows. In Section 2, we propose an arbitrary 1 ↔ 2-qubit asymmetric bidirectional quantum communication protocol, initiated by a mentor. Section 3 is devoted to the construction of the entangled resources required for the proposed protocol using Hadamard, CNOT, and SWAP gates. In Section 4, we set up the quantum circuit for the proposed protocol using Qiskit. Section 5 is devoted to the efficiency analysis of the proposed protocol. Finally, Section 6 concludes the paper with a discussion of the outcomes obtained from the study.

--- Page 2 ---

Within the class of bidirectional teleportation schemes, mentor-initiated protocols provide an additional mechanism for controlling the establishment of the quantum channel. In a mentorinitiated scheme, the mentor is a party who initiates the protocol by participating in the creation of the entangled channel between the sender and receiver. Initially, the sender and receiver do not directly share any entangled quantum channel; rather, the mentor participates in establishing the entanglement needed for subsequent quantum communication. Once the entangled channel has been established, the mentor’s role in the protocol is completed, allowing the sender and receiver to perform quantum teleportation through the established channel.

Improvements for AI systems

  1. This protocol enables the teleportation of an arbitrary one-qubit state from Alice to Bob and an arbitrary two-qubit state from Bob to Alice, meaning AI systems can perform simultaneous, bidirectional transfer of diverse quantum information between two parties without needing prior shared entanglement for the specific transmitted states.

  2. AI systems can maintain a universal applicability to the teleportation of all arbitrary two-qubit states, allowing for complex, high-dimensional data state exchanges that are currently restricted in existing mentor-based protocols which are restricted to specific Bell-like states [11].

Abstract

In this paper, a mentor-initiated bidirectional asymmetric quantum teleportation protocol is proposed. Unlike existing schemes that restrict the two-qubit state transmitted from Bob to Alice to a Bell-like form α00+β11, our protocol allows an arbitrary two-qubit state to be teleported from Bob to Alice within the mentor-initiated framework. The required entangled resources are constructed using standard quantum gates, and the protocol is illustrated through its quantum-circuit implementation in Qiskit. The proposed protocol is further simulated using Qiskit, and the simulation results show probability distributions very close to the theoretically expected values for the chosen input states.

Related papers