generate a significant milestone in quantum teleportation research
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Chapter 1: Breakthrough in Quantum Teleportation
Researchers at the National Institute of Standards and Technology (NIST) have made impressive strides in quantum teleportation, successfully transferring a complete quantum logic operation between two ions. This achievement is a pivotal step toward the realization of large-scale quantum computing.
The NIST team teleported a specific type of computer circuit instruction, known as a quantum logic operation, between two electrically charged atoms, or ions. This experiment illustrates the potential for future quantum networks to execute complex tasks.
Quantum teleportation enables the transfer of information between two quantum systems, even if they are entirely isolated from one another—akin to transferring data between two books stored in separate basements. Unlike the teleportation depicted in science fiction, such as Star Trek, this process only involves the movement of information, not physical matter.
While prior demonstrations of quantum teleportation have been conducted with various quantum systems, this marks the first instance of teleporting a full quantum logic operation using ions. This is particularly noteworthy because ions are considered one of the leading candidates for future quantum computer architectures. The results of this experiment were published in the May 31 issue of Science.
NIST physicist Dietrich Leibfried remarked, “We confirmed that our logic operation functions on all input states of two quantum bits with a probability of 85 to 87%—not perfect, but it's a promising beginning.” The construction of a full-scale quantum computer could potentially solve problems that current classical computers cannot tackle. NIST is actively engaged in global research efforts to leverage quantum behavior for practical applications.
For quantum computers to function effectively, they will likely require millions of quantum bits, or “qubits,” as well as methods to perform operations across qubits in large-scale machines and networks. Teleporting logic operations presents one solution to facilitate these connections without necessitating direct quantum mechanical links. However, physical connections for classical information exchange will still be essential.
How Quantum Teleportation Functions
In their experiment, the NIST team teleported a controlled-NOT (CNOT) logic operation between two beryllium ion qubits, positioned more than 340 micrometers apart within an ion trap. This distance effectively eliminates the possibility of significant direct interaction between the quantum systems.
A CNOT operation changes the state of the second qubit from 0 to 1, or vice versa, but only if the first qubit is in the state of 1—if the first qubit is 0, the second remains unchanged. In a typical quantum scenario, both qubits can exist in “superpositions,” meaning they can have values of both 1 and 0 simultaneously.
The teleportation process relies on entanglement, a phenomenon where the quantum properties of two or more entangled particles remain linked, even when separated by vast distances. The researchers utilized a “messenger” pair of entangled magnesium ions to relay information between the beryllium ions.
The NIST team discovered that their teleported CNOT process entangled the magnesium ions with a success rate of 95%, while the overall logic operation succeeded 85% to 87% of the time. Leibfried stated, “Gate teleportation enables us to perform a quantum logic gate between two ions that may have never interacted before.”
The entangled pairs could potentially be generated in a dedicated section of the quantum computer and transported to qubits requiring connection with a logic gate, even if they are far apart.
NIST's efforts integrated multiple operations in a single experiment that are crucial for the development of large-scale ion-based quantum computers. This includes the control of various ion types, ion transport, and entangling operations on specific subsets of the system. This achievement represents a first for the research community.
To validate that they had indeed performed a CNOT gate, the researchers prepared the first qubit in 16 distinct combinations of input states and measured the outputs on the second qubit. This led to the creation of a generalized quantum “truth table” confirming the process's effectiveness.
In addition to compiling a truth table, the researchers examined data consistency over extended periods to identify error sources in their experimental setup. This approach is anticipated to be a vital tool in characterizing quantum information processes in future studies and signifies another step toward successful quantum computing.
Original Research: Y. Wan, D. Kienzler, S. Erickson, K.H. Mayer, T.R. Tan, J. Wu, H.M. Vasconcelos, S. Glancy, E. Knill, D.J. Wineland, A.C. Wilson, and D. Leibfried. 2019. Quantum gate teleportation between separated zones of a trapped-ion processor. Science. May 31.
Chapter 2: Key Videos on Quantum Teleportation
This video delves into the high-fidelity and fault-tolerant teleportation of a logical qubit using a trapped-ion quantum computer, showcasing the advanced techniques employed in the research.
This video presents experimental evidence for quantum teleportation of energy and negative energy, providing insights into the implications of quantum mechanics on energy transfer.