The paper proposes a quantum information processing scheme based on quantum dot (QD) electron spins coupled through a microcavity mode. The scheme leverages the long decoherence times of conduction band electrons in semiconductors and the cavity-QED techniques to achieve controlled interactions between distant QD spins. Key elements include: 1. **Raman Coupling**: Strong laser fields and a single-mode microcavity mode are used to couple the spin eigenstates of QDs via Raman transitions. 2. **Two-Qubit Operations**: The effective Hamiltonian for two-qubit interactions is derived, showing that Raman coupling through a common cavity mode can establish controllable long-range transverse spin-spin interactions. 3. **Conditional Phase-Flip (CPF) Operation**: This operation can be realized by combining the effective interaction Hamiltonian with one-bit rotations. 4. **Parallel Operations**: The scheme allows for parallel execution of multiple two-qubit operations using a single cavity mode. 5. **Decoherence Considerations**: The primary technological limitation is the short photon lifetime in microcavities, which can be improved through advanced microdisk structures or ultra-high finesse cavities. 6. **Measurement**: Spin states can be measured by detecting single photons leaking from the cavity when the QD spin is in the ground state. The scheme is scalable and potentially useful for quantum computing, with the potential to achieve universal quantum gates and quantum state transfer.The paper proposes a quantum information processing scheme based on quantum dot (QD) electron spins coupled through a microcavity mode. The scheme leverages the long decoherence times of conduction band electrons in semiconductors and the cavity-QED techniques to achieve controlled interactions between distant QD spins. Key elements include: 1. **Raman Coupling**: Strong laser fields and a single-mode microcavity mode are used to couple the spin eigenstates of QDs via Raman transitions. 2. **Two-Qubit Operations**: The effective Hamiltonian for two-qubit interactions is derived, showing that Raman coupling through a common cavity mode can establish controllable long-range transverse spin-spin interactions. 3. **Conditional Phase-Flip (CPF) Operation**: This operation can be realized by combining the effective interaction Hamiltonian with one-bit rotations. 4. **Parallel Operations**: The scheme allows for parallel execution of multiple two-qubit operations using a single cavity mode. 5. **Decoherence Considerations**: The primary technological limitation is the short photon lifetime in microcavities, which can be improved through advanced microdisk structures or ultra-high finesse cavities. 6. **Measurement**: Spin states can be measured by detecting single photons leaking from the cavity when the QD spin is in the ground state. The scheme is scalable and potentially useful for quantum computing, with the potential to achieve universal quantum gates and quantum state transfer.