Experimental realization of nondestructive discrimination of Bell states using a five-qubit quantum computer

Abstract

A scheme for distributed quantum measurement that allows nondestructive or indirect Bell measurement was proposed by Gupta et al., (Int. J. Quant. Infor. 5 (2007) 627) and subsequently realized experimentally using an NMR-based three-qubit quantum computer by Samal et al., (J. Phys. B, 43 (2010) 095508). In the present work, a similar experiment is performed using the five-qubit super-conductivity-based quantum computer, which has been recently placed in cloud by IBM Corporation. The experiment confirmed that the Bell state can be constructed and measured in a nondestructive manner with a reasonably high fidelity. A comparison of the outcomes of this study and the results obtained earlier in the NMR-based experiment has also been performed. The study indicates that to make a scalable SQUID-based computer, errors by the gates (in the present technology) have to be reduced considerably.

Optimization of Circuits for IBM's Five-Qubit Quantum Computers

“…In fact, in Ref. [1] and other recent works using IBM quantum computers it is clearly observed that the state fidelity reduces considerably with the increase in the gate count. Further, because of this fact, each IBM quantum computer imposes a bound on the maximum number of gates that can be used in a single experiment.…”

“…Again, six CNOTs can be realized directly and six can be realized by interchanging the target and control (as explained above.) For the following CNOTs (denoted as a pair of qubits, where the first qubit is the control and the second is the target) {(0, 4), (1,4), (3, 0), (3, 1), (4, 0), (4, 1)} we may exchange the control with qubit 2 at a cost of 10 additional gates using the swap gate approach, or with 9 additional gates using the template approach. Both methods are illustrated with an example below.…”

“…Interest in quantum computing has received a boost with the availability of IBM Quantum Computers (www.research.ibm.com/ibm-q) that enables users to run quantum experiments. Recently, various computational tasks (e.g., Bell state discrimination [1], teleportation using optimal quantum resources [2], quantum permutation algorithm [3], quantum cheque [4], testing Mermin inequalities [5], etc.) have been realized using IBM Quantum Computers.…”

Quantum robots can fly; play games: an IBM quantum experience

“…Recently, IBM has developed different types of prototypes of quantum processors and they are available by a free web based interface called IBM Quantum Experience (IBM QE). Researchers have taken a proper advantage of it by demonstrating and running a variety of quantum computing experiments, e.g., [10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29]. Here, we use IBM's 5-qubit quantum processor, 'ibmqx4' to design the quantum circuit and perform the experiment by simulating it.…”

Demonstration of the Quantum No-Hiding Theorem in a Category Theoretic Framework: An IBM Quantum Experience

“…It is world's first commercial quantum computing service provided by IBM, and permits a user to run quantum algorithms via the IBM cloud and implement quantum circuits. Using this web interface researchers have run a variety of quantum computing experiments and demonstrations, e.g., [2][3][4][5][6][7][8][9][10][11].…”