Mun Dae Kim

Macroscopic Greenberger-Horne-Zeilinger and W states in flux qubits

We investigate two types of genuine three-qubit entanglement, known as the Greenberger-Horne-Zeilinger (GHZ) and W states, in a macroscopic quantum system. Superconducting flux qubits are theoretically considered in order to generate such states. A phase coupling is proposed to offer enough strength of interactions between qubits. While an excited state can be the W state, the GHZ state is formed at the ground state of the three flux qubits. The GHZ and W states are shown to be robust against external flux fluctuations for feasible experimental realizations.

Sondheimer oscillation as a signature of surface Dirac fermions

Topological states of matter challenge the paradigm of symmetry breaking, characterized by gapless boundary modes and protected by the topological property of the ground state. Recently, angle-resolved photoemission spectroscopy (ARPES) has revealed that semiconductors of Bi

Coupling of Josephson current qubits using a connecting loop

_{2}

Implementation of a three-qubit Toffoli gate in a single step

Se

Coupling qubits in circuit-QED cavities connected by a bridge qubit

_{3}

Mesoscopic Luttinger liquid theory in an Aharonov-Bohm ring

and Bi

Diamagnetic response of Aharonov-Bohm rings : Impurity backward scattering

_{2}

Scalable quantum computing using persistent current qubits with Josephson junctions

Te

Time-dependent functional Schrödinger picture approach to many-particle systems

_{3}

Commensurate quantum oscillations in coupled qubits

belong to such a class of materials. Here, we present undisputable evidence for the existence of gapless surface Dirac fermions from transport in Bi