NEC & RIKEN Realize World's First Quantum Logic Gate
in a Two-Qubit Solid-State Device

- Realization of an elementary circuit which practical quantum computers consist of -

TOKYO, October 30, 2003 - NEC Corporation (President: Akinobu Kanasugi) and the RIKEN Institute of Physical and Chemical Research (President: Ryoji Noyori) announced today that in jointly conducted experimentation a quantum logic gate operation has been successfully demonstrated in a solid-state device consisting of two coupled quantum bit (qubits). This is a world's first, and represents a major step toward the realization of practical quantum computing. This result was achieved by the research group headed by Jaw-Shen Tsai of the NEC Fundamental Research Laboratory, and the RIKEN Institute of Physical and Chemical Research (the Macroscopic Quantum Coherence Laboratory). The details of present research results will be published in the October 30 issue of the British science journal 'Nature'.

The quantum computer, when it is finally brought to fruition, will likely far surpass the capabilities of even the most modern of today's supercomputers, as it utilizes a "qubit," a quantum superposition of the "0" and "1" states, as the basic information unit. Information processing in a quantum computer is conducted by a series of quantum gate operations to the qubit, and it has been theoretically proven that only two kinds of gate operations are sufficient for quantum computation, no matter how complicated the algorithms are and no matter how many qubits they require. The two gates are the one-qubit rotation gate which controls the state of one qubit, and the controlled-NOT (C-NOT) gate which works as a conditional gate for two qubits. In 1999, NEC succeeded in controlling the quantum state of one qubit made of small superconductors. This was the first demonstration of the one-qubit rotation gate in solid state devices. Then in February of 2003, a joint NEC/RIKEN laboratory demonstrated the world's first quantum entanglement in a 2-qubit solid-state device. However, to date no one has succeeded in realizing the above-mentioned two-qubit conditional gate. Now NEC and RIKEN have proposed a new scheme to implement the C-NOT gate using a similar type of two-qubit circuit made of superconductors, and have experimentally demonstrated that it works properly as a logic gate for two qubits.

Having succeeded in realizing both the one-qubit rotation gate and the two-qubit conditional gate, the research laboratory will continue to strive toward achieving further integration of the qubit to demonstrate quantum algorithm, an effort which is expected to contribute significantly to the practical realization of a quantum computer.

About NEC Corporation
NEC Corporation (NASDAQ: NIPNY) (FTSE: 6701q.l) is one of the world's leading providers of Internet, broadband network and enterprise business solutions dedicated to meeting the specialized needs of its diverse and global base of customers. Ranked as one of the world's top patent-producing companies, NEC delivers tailored solutions in the key fields of computer, networking and electron devices, by integrating its technical strengths in IT and Networks, and by providing advanced semiconductor solutions through NEC Electronics Corporation. The NEC Group employs more than 140,000 people worldwide and had net sales of approximately $40 billion in the fiscal year ended March 2003. For additional information, please visit the NEC home page at: http://www.nec.com.

About RIKEN(The Institute of Physical and Chemical Research)
RIKEN is a public corporation supported by the government. It is engaged in research over a wide range of fields such as physics, chemistry, bioscience, engineering, etc. from a very fundamental level to immediate application. For additional information, please visit the RIKEN home page at http://www.riken.go.jp/.

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Press contact:

NEC Corporation Diane Foley Corporate Communications Division Phone: +81-3-3798-6511(direct) Fax: +81-3-3457-7249 Email: d-foley@ax.jp.nec.com

RIKEN Hidehiro Komai Public Relations Office Phone: +81-48-467-9272(direct) Fax: +81-48-462-4715 Email: h-komai@postman.riken.go.jp