{"doi":"10.1038/nature04235","title":"Experimental observation of the quantum Hall effect and Berry's phase in graphene","abstract":"When electrons are confined in two-dimensional materials, quantum-mechanically enhanced transport phenomena such as the quantum Hall effect can be observed. Graphene, consisting of an isolated single atomic layer of graphite, is an ideal realization of such a two-dimensional system. However, its behaviour is expected to differ markedly from the well-studied case of quantum wells in conventional semiconductor interfaces. This difference arises from the unique electronic properties of graphene, which exhibits electron-hole degeneracy and vanishing carrier mass near the point of charge neutrality. Indeed, a distinctive half-integer quantum Hall effect has been predicted theoretically, as has the existence of a non-zero Berry's phase (a geometric quantum phase) of the electron wavefunction--a consequence of the exceptional topology of the graphene band structure. Recent advances in micromechanical extraction and fabrication techniques for graphite structures now permit such exotic two-dimensional electron systems to be probed experimentally. Here we report an experimental investigation of magneto-transport in a high-mobility single layer of graphene. Adjusting the chemical potential with the use of the electric field effect, we observe an unusual half-integer quantum Hall effect for both electron and hole carriers in graphene. The relevance of Berry's phase to these experiments is confirmed by magneto-oscillations. In addition to their purely scientific interest, these unusual quantum transport phenomena may lead to new applications in carbon-based electronic and magneto-electronic devices.","journal":"Nature","year":2005,"id":2998,"datarank":30.486118829370593,"base_score":9.502711433914095,"endowment":9.502711433914095,"self_citation_contribution":1.4254067150871146,"citation_network_contribution":29.06071211428348,"self_endowment_contribution":1.4254067150871146,"citer_contribution":29.06071211428348,"corpus_percentile":99.2,"corpus_rank":543,"citation_count":13395,"citer_count":188,"citers_with_citation_signal":188,"citers_with_endowment":188,"datacite_reuse_total":0,"is_dataset":false,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2005-11-01","authors":[{"id":33212,"name":"Yan-Wen Tan","orcid":null,"position":1,"is_corresponding":false},{"id":33213,"name":"Horst L. Stormer","orcid":null,"position":2,"is_corresponding":false},{"id":33214,"name":"Philip Kim","orcid":"0000-0002-8255-0086","position":3,"is_corresponding":false},{"id":33215,"name":"Yan‐Wen Tan","orcid":"0000-0002-5522-7996","position":4,"is_corresponding":false},{"id":33216,"name":"H. L. Störmer","orcid":null,"position":5,"is_corresponding":false},{"id":33211,"name":"Yuanbo Zhang","orcid":"0000-0003-4745-8038","position":0,"is_corresponding":true}],"reference_count":20,"raw_metadata":{"citation_network_status":"fetched"},"created_at":"2026-03-01T18:20:47.508186Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}