{"id":995,"date":"2026-10-17T08:00:00","date_gmt":"2026-10-16T23:00:00","guid":{"rendered":"https:\/\/quantumsea.net\/?p=995"},"modified":"2026-10-17T06:46:47","modified_gmt":"2026-10-16T21:46:47","slug":"qs-quantum-state-fidelity-trace-distance-20261017","status":"publish","type":"post","link":"https:\/\/quantumsea.net\/?p=995","title":{"rendered":"\u5fe0\u5b9f\u5ea6\u3068\u30c8\u30ec\u30fc\u30b9\u8ddd\u96e2\u3001\u91cf\u5b50\u72b6\u614b\u306e\u9055\u3044\u3092\u4e8c\u3064\u306e\u6307\u6a19\u3067\u8aad\u3080"},"content":{"rendered":"<p>\u91cf\u5b50\u72b6\u614b\u304c\u76ee\u6a19\u306b\u3069\u308c\u307b\u3069\u8fd1\u3044\u304b\u3092\u8868\u3059\u3068\u304d\u3001\u300c\u5fe0\u5b9f\u5ea6\u300d\u3068\u3044\u3046\u6570\u5024\u304c\u3088\u304f\u4f7f\u308f\u308c\u307e\u3059\u3002\u3057\u304b\u3057\u3001\u540c\u3058\u76ee\u6a19\u3078\u306e\u5fe0\u5b9f\u5ea6\u304c\u7b49\u3057\u304f\u3066\u3082\u3001\u72b6\u614b\u304c\u540c\u3058\u3068\u306f\u9650\u308a\u307e\u305b\u3093\u3002\u6e2c\u308a\u65b9\u3092\u5909\u3048\u308b\u3068\u3001\u4e00\u65b9\u3067\u306f\u51fa\u3084\u3059\u304f\u3001\u3082\u3046\u4e00\u65b9\u3067\u306f\u51fa\u306b\u304f\u3044\u7d50\u679c\u304c\u898b\u3064\u304b\u308b\u3053\u3068\u3082\u3042\u308a\u307e\u3059\u3002<\/p>\n<p>\u3053\u306e\u9055\u3044\u3092\u3001<strong>\u5fe0\u5b9f\u5ea6\u3068\u30c8\u30ec\u30fc\u30b9\u8ddd\u96e2<\/strong>\u3068\u3044\u3046\u4e8c\u3064\u306e\u6307\u6a19\u3067\u898b\u3066\u307f\u307e\u3059\u3002\u91cf\u5b50\u8a08\u7b97\u7528\u30bd\u30d5\u30c8\u30a6\u30a7\u30a2QuTiP\u306e\u5b9a\u7fa9\u3092\u624b\u304c\u304b\u308a\u306b\u30011\u91cf\u5b50\u30d3\u30c3\u30c8\u306e\u5c0f\u3055\u306a\u884c\u5217\u3060\u3051\u3067\u8a08\u7b97\u3067\u304d\u308b\u4f8b\u3092\u4f7f\u3044\u307e\u3059\u3002<\/p>\n<section class=\"influvetor-quick-summary\">\n<p><strong>\u7c21\u5358\u306b\u307e\u3068\u3081\u308b\u3068\uff1f<\/strong><\/p>\n<ul>\n<li>\u5fe0\u5b9f\u5ea6\u306f\u3001\u5e73\u65b9\u6839\u3092\u53d6\u308b\u5b9a\u7fa9\u3068\u3001\u305d\u306e\u4e8c\u4e57\u3092\u4f7f\u3046\u5b9a\u7fa9\u3092\u533a\u5225\u3057\u307e\u3059\u3002\u540c\u3058\u540d\u524d\u3067\u3082\u6570\u5024\u3092\u305d\u306e\u307e\u307e\u6bd4\u8f03\u3067\u304d\u308b\u3068\u306f\u9650\u308a\u307e\u305b\u3093\u3002<\/li>\n<li>\u76ee\u6a19\u3078\u306e\u5fe0\u5b9f\u5ea6\u304c\u540c\u3058\u4e8c\u3064\u306e\u72b6\u614b\u3067\u3082\u3001\u5225\u306e\u6e2c\u5b9a\u3067\u5f97\u3089\u308c\u308b\u78ba\u7387\u3084\u3001\u76ee\u6a19\u307e\u3067\u306e\u30c8\u30ec\u30fc\u30b9\u8ddd\u96e2\u306f\u5909\u308f\u308a\u307e\u3059\u3002<\/li>\n<li>\u7d14\u7c8b\u72b6\u614b\u540c\u58eb\u3067\u4f7f\u3048\u308b\u95a2\u4fc2\u5f0f\u3092\u3001\u6df7\u5408\u72b6\u614b\u3092\u542b\u3080\u6bd4\u8f03\u3078\u5e83\u3052\u306a\u3044\u3053\u3068\u304c\u5927\u5207\u3067\u3059\u3002<\/li>\n<\/ul>\n<\/section>\n<h2>\u6700\u521d\u306b\u300c\u4f55\u3092\u5fe0\u5b9f\u5ea6\u3068\u547c\u3076\u304b\u300d\u3092\u305d\u308d\u3048\u308b<\/h2>\n<p>\u91cf\u5b50\u72b6\u614b\u3092\u307e\u3068\u3081\u3066\u8868\u3059\u9053\u5177\u304c\u3001\u5bc6\u5ea6\u884c\u5217\u3067\u3059\u30021\u91cf\u5b50\u30d3\u30c3\u30c8\u306a\u30892\u00d72\u306e\u884c\u5217\u3067\u3001\u3069\u306e\u6e2c\u5b9a\u304b\u3089\u3069\u306e\u7d50\u679c\u304c\u5f97\u3089\u308c\u308b\u304b\u3068\u3044\u3046\u78ba\u7387\u3092\u8a08\u7b97\u3067\u304d\u307e\u3059\u3002\u7279\u5b9a\u306e\u72b6\u614b\u30d9\u30af\u30c8\u30eb\u3067\u8868\u305b\u308b<strong>\u7d14\u7c8b\u72b6\u614b<\/strong>\u3082\u3001\u8907\u6570\u306e\u72b6\u614b\u3092\u78ba\u7387\u7684\u306b\u6df7\u305c\u305f<strong>\u6df7\u5408\u72b6\u614b<\/strong>\u3082\u6271\u3048\u307e\u3059\u3002<\/p>\n<p>\u4e8c\u3064\u306e\u5bc6\u5ea6\u884c\u5217\u3092\u03c1\u3068\u03c3\u3068\u66f8\u304f\u3068\u3001\u3053\u306e\u8a18\u4e8b\u3067\u306f\u5fe0\u5b9f\u5ea6\u3092\u6b21\u306eF\u3067\u8868\u3057\u307e\u3059\u3002<\/p>\n<p><code>F(\u03c1, \u03c3) = Tr \u221a(\u221a\u03c1 \u03c3 \u221a\u03c1)<\/code><\/p>\n<p>Tr\u306f\u884c\u5217\u306e\u5bfe\u89d2\u6210\u5206\u3092\u8db3\u3059\u64cd\u4f5c\u3067\u3059\u3002\u221a\u03c1\u306f\u3001\u5404\u6210\u5206\u3092\u5225\u3005\u306b\u5e73\u65b9\u6839\u306b\u3059\u308b\u306e\u3067\u306f\u306a\u304f\u3001\u884c\u5217\u3068\u3057\u3066\u306e\u5e73\u65b9\u6839\u3092\u610f\u5473\u3057\u307e\u3059\u3002\u3053\u3053\u3067\u4f7f\u3046\u306e\u306f\u3001\u6b63\u3057\u304f\u6b63\u898f\u5316\u3055\u308c\u305f\u3001\u540c\u3058\u6b21\u5143\u30fb\u540c\u3058\u57fa\u5e95\u3067\u8868\u3055\u308c\u305f\u5bc6\u5ea6\u884c\u5217\u3067\u3059\u3002<\/p>\n<p>QuTiP 5.1.1\u306e\u56fa\u5b9a\u7248\u3067\u78ba\u8a8d\u3057\u305f<code>fidelity<\/code>\u306f\u3001\u3053\u306e\u5e73\u65b9\u6839\u3092\u53d6\u308b\u5074\u306e\u5b9a\u7fa9\u3067\u3059\u3002\u4e00\u65b9\u3001F\u00b2\u3092\u5fe0\u5b9f\u5ea6\u3068\u547c\u3076\u6587\u732e\u3082\u3042\u308a\u307e\u3059\u3002\u4f8b\u3048\u3070F\u304c\u7d040.9487\u306a\u3089F\u00b2\u306f0.9\u3067\u3059\u3002\u5b9a\u7fa9\u304c\u9055\u3046\u3060\u3051\u306e\u4e8c\u3064\u306e\u6570\u5024\u3092\u898b\u3066\u3001\u300c0.9\u306e\u65b9\u304c\u54c1\u8cea\u304c\u4f4e\u3044\u300d\u3068\u306f\u5224\u65ad\u3067\u304d\u307e\u305b\u3093\u3002<sup class=\"source-note\">[1][2]<\/sup><\/p>\n<p>\u307e\u305f\u3001\u3053\u3053\u3067\u6bd4\u8f03\u3059\u308b\u306e\u306f<strong>\u91cf\u5b50\u72b6\u614b<\/strong>\u3067\u3059\u3002\u91cf\u5b50\u64cd\u4f5c\u3092\u6bd4\u3079\u308b\u30d7\u30ed\u30bb\u30b9\u5fe0\u5b9f\u5ea6\u3084\u5e73\u5747\u30b2\u30fc\u30c8\u5fe0\u5b9f\u5ea6\u3068\u306f\u5bfe\u8c61\u304c\u7570\u306a\u308b\u305f\u3081\u3001\u305d\u308c\u3089\u306e\u6570\u5024\u3068\u306e\u63db\u7b97\u306b\u306f\u8e0f\u307f\u8fbc\u307f\u307e\u305b\u3093\u3002<\/p>\n<h2>\u76ee\u6a19\u3078\u306e\u91cd\u306a\u308a\u304c\u540c\u3058\u4e8c\u3064\u306e\u72b6\u614b<\/h2>\n<p>\u76ee\u6a19\u3092|0\u3009\u3068\u3057\u3001\u57fa\u5e95\u306e\u9806\u5e8f\u3092|0\u3009\u3001|1\u3009\u306b\u56fa\u5b9a\u3057\u307e\u3059\u3002\u76ee\u6a19\u306e\u5bc6\u5ea6\u884c\u5217\u306f\u03c3\uff1d[[1, 0], [0, 0]]\u3067\u3059\u3002\u3053\u308c\u3068\u6bd4\u8f03\u3059\u308b\u4e8c\u3064\u306e\u72b6\u614b\u3092\u7528\u610f\u3057\u307e\u3059\u3002<\/p>\n<p><strong>A\u306f\u3001|0\u3009\u309290%\u3001|1\u3009\u309210%\u306e\u78ba\u7387\u3067\u6df7\u305c\u305f\u72b6\u614b<\/strong>\u3067\u3059\u3002\u305d\u306e\u5bc6\u5ea6\u884c\u5217\u306f\u6b21\u306e\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<pre style=\"overflow-x:auto\">\u03c1A = [ 0.9   0   ]\n     [ 0     0.1 ]<\/pre>\n<p><strong>B\u306f\u3001\u221a0.9|0\u3009\uff0b\u221a0.1|1\u3009\u3068\u3044\u3046\u4e00\u3064\u306e\u7d14\u7c8b\u72b6\u614b<\/strong>\u3067\u3059\u3002\u884c\u5217\u306b\u3059\u308b\u3068\u3001\u5bfe\u89d2\u4ee5\u5916\u306b\u30820.3\u304c\u73fe\u308c\u307e\u3059\u3002<\/p>\n<pre style=\"overflow-x:auto\">\u03c1B = [ 0.9   0.3 ]\n     [ 0.3   0.1 ]<\/pre>\n<p>A\u3068B\u306e\u5bfe\u89d2\u6210\u5206\u306f\u540c\u3058\u3067\u3059\u3002|0\u3009\u304b|1\u3009\u304b\u3092\u533a\u5225\u3059\u308b\u6e2c\u5b9a\u3001\u3044\u308f\u3086\u308bZ\u57fa\u5e95\u3067\u306e\u6e2c\u5b9a\u306a\u3089\u3001\u3069\u3061\u3089\u3082|0\u3009\u304c\u51fa\u308b\u78ba\u7387\u306f0.9\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<p>\u4eca\u56de\u306e\u3088\u3046\u306b\u76ee\u6a19\u304c\u7d14\u7c8b\u72b6\u614b|0\u3009\u3067\u3042\u308b\u3068\u304d\u3001\u5fe0\u5b9f\u5ea6\u306e\u4e8c\u4e57\u306f<code>F\u00b2 = \u30080|\u03c1|0\u3009<\/code>\u3067\u3059\u3002\u3053\u306e\u4f8b\u3067\u306f\u884c\u5217\u306e\u5de6\u4e0a\u3092\u8aad\u3081\u3070\u3088\u304f\u3001A\u3082B\u3082F\u00b2\uff1d0.9\u3001F\uff1d\u221a0.9\u22520.9487\u3067\u3059\u3002\u305f\u3060\u3057\u3001F\u00b2\u3092\u3053\u306e\u6e2c\u5b9a\u78ba\u7387\u3068\u3057\u3066\u8aad\u3081\u308b\u306e\u306f\u3001\u6307\u5b9a\u3057\u305f\u7d14\u7c8b\u306a\u76ee\u6a19\u3078\u306e\u5c04\u5f71\u3068\u3044\u3046\u6761\u4ef6\u304c\u3042\u308b\u304b\u3089\u3067\u3059\u3002\u4e00\u822c\u306e\u5fe0\u5b9f\u5ea6\u3092\u3001\u305d\u306e\u307e\u307e\u88c5\u7f6e\u306e\u6210\u529f\u7387\u3068\u547c\u3076\u3053\u3068\u306f\u3067\u304d\u307e\u305b\u3093\u3002<\/p>\n<p>\u4e8c\u3064\u306e\u884c\u5217\u306e\u9055\u3044\u306f\u3001\u5bfe\u89d2\u4ee5\u5916\u306e\u6210\u5206\u306b\u3042\u308a\u307e\u3059\u3002B\u306e0.3\u306f\u3001\u3053\u306e\u57fa\u5e95\u3067\u306e\u91cd\u306d\u5408\u308f\u305b\u306b\u95a2\u308f\u308b<strong>\u30b3\u30d2\u30fc\u30ec\u30f3\u30b9<\/strong>\u3092\u8868\u3057\u307e\u3059\u3002A\u3067\u306f\u305d\u306e\u6210\u5206\u304c0\u3067\u3059\u3002\u5bfe\u89d2\u306e\u78ba\u7387\u3060\u3051\u3092\u305d\u308d\u3048\u3066\u3082\u3001\u884c\u5217\u5168\u4f53\u307e\u3067\u306f\u305d\u308d\u3044\u307e\u305b\u3093\u3002<\/p>\n<figure><a href=\"https:\/\/quantumsea.net\/wp-content\/uploads\/2026\/10\/qs-quantum-state-fidelity-trace-distance-20261017-source-figure-1-1f396912275b.png\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/quantumsea.net\/wp-content\/uploads\/2026\/10\/qs-quantum-state-fidelity-trace-distance-20261017-source-figure-1-1f396912275b.png\" width=\"1080\" height=\"1440\" style=\"max-width:100%;height:auto\" alt=\"\u76ee\u6a19\u306f|0\u3009\u3002A\u306f\u5bfe\u89d20.9\u30010.1\u306e\u6df7\u5408\u72b6\u614b\u3001B\u306f\u540c\u3058\u5bfe\u89d2\u3068\u975e\u5bfe\u89d20.3\u306e\u7d14\u7c8b\u72b6\u614b\u3002\u3069\u3061\u3089\u3082F\u306e\u4e8c\u4e57\u306f0.9\u3060\u304c\u3001\u30c8\u30ec\u30fc\u30b9\u8ddd\u96e2\u306fA\u304c0.1\u3001B\u304c\u7d040.3162\u3002X\u57fa\u5e95\u3067\u30d7\u30e9\u30b9\u304c\u51fa\u308b\u78ba\u7387\u306fA\u304c0.5\u3001B\u304c0.8\u3002\"><\/a><figcaption>\u56f31\u3000\u76ee\u6a19\u3078\u306e\u5fe0\u5b9f\u5ea6\u304c\u540c\u3058\u3067\u3082\u3001\u72b6\u614b\u5168\u4f53\u306f\u540c\u3058\u306b\u306a\u3089\u306a\u3044\u4f8b\u3002\u6307\u5b9a\u3057\u305f\u7406\u60f3\u7684\u306a\u5bc6\u5ea6\u884c\u5217\u304b\u3089\u306e\u72ec\u81ea\u8a08\u7b97\u3067\u3001\u5b9f\u6a5f\u306e\u6e2c\u5b9a\u5024\u3067\u306f\u3042\u308a\u307e\u305b\u3093\u3002\u539f\u5bf8\u753b\u50cf\u3092\u958b\u3051\u307e\u3059\u3002<\/figcaption><\/figure>\n<h2>\u6e2c\u308a\u65b9\u3092\u5909\u3048\u308b\u3068\u3001\u9055\u3044\u304c\u78ba\u7387\u306b\u73fe\u308c\u308b<\/h2>\n<p>\u6b21\u306f\u3001|\uff0b\u3009\uff1d(|0\u3009\uff0b|1\u3009)\/\u221a2\u3068\u3001\u305d\u306e\u76f4\u4ea4\u3059\u308b|\u2212\u3009\u3092\u533a\u5225\u3059\u308bX\u57fa\u5e95\u3067\u6e2c\u308a\u307e\u3059\u3002|\uff0b\u3009\u304c\u51fa\u308b\u78ba\u7387\u306f<code>\u3008\uff0b|\u03c1|\uff0b\u3009<\/code>\u3067\u3059\u3002\u4eca\u56de\u306e\u5b9f\u6570\u306e\u884c\u5217\u3067\u306f\u3001\u56db\u3064\u306e\u6210\u5206\u3092\u8db3\u3057\u30662\u3067\u5272\u308b\u8a08\u7b97\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<p>A\u3067\u306f<code>(0.9\uff0b0\uff0b0\uff0b0.1)\/2\uff1d0.5<\/code>\u3067\u3059\u3002B\u3067\u306f\u975e\u5bfe\u89d2\u6210\u5206\u3082\u5bc4\u4e0e\u3057\u3066\u3001<code>(0.9\uff0b0.3\uff0b0.3\uff0b0.1)\/2\uff1d0.8<\/code>\u306b\u306a\u308a\u307e\u3059\u3002Z\u57fa\u5e95\u3067\u306f\u898b\u5206\u3051\u3089\u308c\u306a\u304b\u3063\u305f\u9055\u3044\u304c\u3001X\u57fa\u5e95\u306e\u4e88\u6e2c\u306b\u306f\u73fe\u308c\u307e\u3057\u305f\u3002<\/p>\n<p>\u3053\u308c\u306f\u3001\u5b9f\u969b\u306b\u4f55\u56de\u6e2c\u3063\u3066\u3082\u5fc5\u305a50%\u308480%\u306b\u306a\u308b\u3068\u3044\u3046\u610f\u5473\u3067\u306f\u3042\u308a\u307e\u305b\u3093\u3002\u6307\u5b9a\u3057\u305f\u72b6\u614b\u304b\u3089\u8a08\u7b97\u3057\u305f\u7406\u60f3\u7684\u306a\u78ba\u7387\u3067\u3059\u3002\u6709\u9650\u56de\u306e\u6e2c\u5b9a\u7d50\u679c\u306b\u306f\u3070\u3089\u3064\u304d\u304c\u3042\u308a\u3001\u72b6\u614b\u3092\u5b9f\u9a13\u30c7\u30fc\u30bf\u304b\u3089\u63a8\u5b9a\u3059\u308b\u306b\u306f\u3001\u305d\u306e\u4e0d\u78ba\u304b\u3055\u3092\u5225\u306b\u6271\u3046\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<h2>\u30c8\u30ec\u30fc\u30b9\u8ddd\u96e2\u306f\u3001\u76ee\u6a19\u3068\u306e\u5dee\u3092\u884c\u5217\u5168\u4f53\u3067\u8a08\u7b97\u3059\u308b<\/h2>\n<p>\u30c8\u30ec\u30fc\u30b9\u8ddd\u96e2D\u306f\u3001\u4e8c\u3064\u306e\u884c\u5217\u306e\u5dee\u0394\uff1d\u03c1\u2212\u03c3\u304b\u3089\u8a08\u7b97\u3057\u307e\u3059\u3002QuTiP\u306e<code>tracedist<\/code>\u306b\u5bfe\u5fdc\u3059\u308b\u5b9a\u7fa9\u306f\u6b21\u306e\u3068\u304a\u308a\u3067\u3059\u3002<sup class=\"source-note\">[2]<\/sup><\/p>\n<p><code>D(\u03c1, \u03c3) = \u00bd Tr \u221a(\u0394\u2020\u0394)<\/code><\/p>\n<p>\u2020\u306f\u8907\u7d20\u5171\u5f79\u3092\u53d6\u3063\u3066\u8ee2\u7f6e\u3059\u308b\u64cd\u4f5c\u3067\u3059\u3002\u5bc6\u5ea6\u884c\u5217\u306e\u5dee\u0394\u306f\u30a8\u30eb\u30df\u30fc\u30c8\u884c\u5217\u306a\u306e\u3067\u3001\u3053\u306e\u5f0f\u306f\u0394\u306e\u56fa\u6709\u5024\u306e\u7d76\u5bfe\u5024\u3092\u8db3\u3057\u30012\u3067\u5272\u308b\u8a08\u7b97\u306b\u3082\u306a\u308a\u307e\u3059\u3002\u5404\u6210\u5206\u306e\u5dee\u3092\u305f\u3060\u8db3\u3059\u65b9\u6cd5\u3068\u306f\u7570\u306a\u308a\u307e\u3059\u3002<\/p>\n<p>A\u3068\u76ee\u6a19\u306e\u5dee\u306f\u5bfe\u89d2\u6210\u5206\u304c\u22120.1\u30680.1\u3067\u3001\u56fa\u6709\u5024\u3082\u3053\u306e\u4e8c\u3064\u3067\u3059\u3002\u305d\u306e\u7d76\u5bfe\u5024\u3092\u8db3\u3057\u30662\u3067\u5272\u308b\u3068\u3001D\uff1d0.1\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<p>B\u3068\u76ee\u6a19\u306e\u5dee\u306f[[\u22120.1, 0.3], [0.3, 0.1]]\u3067\u3059\u3002\u3053\u306e\u884c\u5217\u3092\u4e8c\u4e57\u3059\u308b\u3068\u3001\u5bfe\u89d2\u6210\u5206\u304c0.1\u3001\u975e\u5bfe\u89d2\u6210\u5206\u304c0\u306b\u306a\u308a\u307e\u3059\u3002\u56fa\u6709\u5024\u306f\u2212\u221a0.1\u3068\u221a0.1\u306a\u306e\u3067\u3001D\uff1d\u221a0.1\u22520.3162\u3067\u3059\u3002\u540c\u3058\u5fe0\u5b9f\u5ea6\u3060\u3063\u305f\u4e8c\u3064\u306e\u72b6\u614b\u306b\u3001\u7570\u306a\u308b\u8ddd\u96e2\u304c\u5f97\u3089\u308c\u307e\u3057\u305f\u3002<\/p>\n<div style=\"overflow-x:auto\">\n<table>\n<thead>\n<tr>\n<th>\u76ee\u6a19|0\u3009\u3068\u306e\u6bd4\u8f03<\/th>\n<th>A\uff1a\u78ba\u7387\u7684\u306a\u6df7\u5408<\/th>\n<th>B\uff1a\u7d14\u7c8b\u306a\u91cd\u306d\u5408\u308f\u305b<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<th>F\u00b2<\/th>\n<td>0.9<\/td>\n<td>0.9<\/td>\n<\/tr>\n<tr>\n<th>F<\/th>\n<td>\u221a0.9 \u2252 0.9487<\/td>\n<td>\u221a0.9 \u2252 0.9487<\/td>\n<\/tr>\n<tr>\n<th>\u30c8\u30ec\u30fc\u30b9\u8ddd\u96e2D<\/th>\n<td>0.1<\/td>\n<td>\u221a0.1 \u2252 0.3162<\/td>\n<\/tr>\n<tr>\n<th>Z\u57fa\u5e95\u3067|0\u3009\u304c\u51fa\u308b\u78ba\u7387<\/th>\n<td>0.9<\/td>\n<td>0.9<\/td>\n<\/tr>\n<tr>\n<th>X\u57fa\u5e95\u3067|\uff0b\u3009\u304c\u51fa\u308b\u78ba\u7387<\/th>\n<td>0.5<\/td>\n<td>0.8<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p>\u3053\u306e\u8868\u304b\u3089\u300c\u6df7\u5408\u72b6\u614b\u306e\u65b9\u304c\u5e38\u306b\u3088\u3044\u300d\u3068\u306f\u8a00\u3048\u307e\u305b\u3093\u3002A\u306f\u3001\u3053\u306e\u76ee\u6a19\u306b\u5bfe\u3059\u308b\u30c8\u30ec\u30fc\u30b9\u8ddd\u96e2\u3067\u306fB\u3088\u308a\u8fd1\u3044\u72b6\u614b\u3067\u3059\u3002\u4e00\u65b9\u3001B\u306e\u91cd\u306d\u5408\u308f\u305b\u3092\u5229\u7528\u3057\u305f\u3044\u7528\u9014\u3067\u3001\u975e\u5bfe\u89d2\u6210\u5206\u3092\u5931\u3063\u305fA\u3092\u305d\u306e\u307e\u307e\u4ee3\u308f\u308a\u306b\u3067\u304d\u308b\u3068\u306f\u9650\u308a\u307e\u305b\u3093\u3002\u6bd4\u8f03\u3059\u308b\u76ee\u6a19\u3068\u3001\u5fc5\u8981\u306a\u6027\u8cea\u3092\u6c7a\u3081\u3066\u304b\u3089\u6307\u6a19\u3092\u8aad\u307f\u307e\u3059\u3002<\/p>\n<h2>\u7d14\u7c8b\u72b6\u614b\u540c\u58eb\u306e\u95a2\u4fc2\u5f0f\u306b\u306f\u3001\u4f7f\u3048\u308b\u7bc4\u56f2\u304c\u3042\u308b<\/h2>\n<p>\u4e8c\u3064\u3068\u3082\u7d14\u7c8b\u72b6\u614b\u306a\u3089\u3001\u3053\u306e\u8a18\u4e8b\u306eF\u306e\u5b9a\u7fa9\u3067<code>D\uff1d\u221a(1\u2212F\u00b2)<\/code>\u304c\u6210\u308a\u7acb\u3061\u307e\u3059\u3002QuTiP\u306e\u30ac\u30a4\u30c9\u3082\u3001\u7d14\u7c8b\u72b6\u614b\u540c\u58eb\u306e\u6761\u4ef6\u3092\u4ed8\u3051\u3066\u3053\u306e\u95a2\u4fc2\u3092\u793a\u3057\u3066\u3044\u307e\u3059\u3002<sup class=\"source-note\">[1]<\/sup><\/p>\n<p>B\u3068\u76ee\u6a19\u306f\u3069\u3061\u3089\u3082\u7d14\u7c8b\u72b6\u614b\u306a\u306e\u3067\u3001F\u00b2\uff1d0.9\u304b\u3089D\uff1d\u221a0.1\u3092\u5f97\u3089\u308c\u307e\u3059\u3002\u3057\u304b\u3057\u3001A\u306f\u6df7\u5408\u72b6\u614b\u3067\u3059\u3002\u540c\u3058\u5f0f\u3092\u5f53\u3066\u306f\u3081\u308b\u3068\u7d040.3162\u3068\u306a\u308a\u3001\u76f4\u63a5\u8a08\u7b97\u3057\u305f0.1\u3068\u4e00\u81f4\u3057\u307e\u305b\u3093\u3002\u5fe0\u5b9f\u5ea6\u3060\u3051\u304b\u3089\u3053\u306e\u7b49\u5f0f\u3067\u8ddd\u96e2\u3092\u6c42\u3081\u308b\u524d\u306b\u3001\u4e21\u65b9\u306e\u72b6\u614b\u304c\u7d14\u7c8b\u304b\u3092\u78ba\u304b\u3081\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<h2>\u6570\u5024\u306e\u6a2a\u306b\u3001\u6bd4\u8f03\u6761\u4ef6\u3092\u6b8b\u3059<\/h2>\n<p>\u91cf\u5b50\u72b6\u614b\u3092\u6bd4\u8f03\u3059\u308b\u5831\u544a\u3084\u8a08\u7b97\u3067\u306f\u3001\u307e\u305a\u5fe0\u5b9f\u5ea6\u304cF\u3068F\u00b2\u306e\u3069\u3061\u3089\u304b\u3092\u78ba\u8a8d\u3057\u307e\u3059\u3002\u6b21\u306b\u3001\u6bd4\u8f03\u5bfe\u8c61\u306e\u72b6\u614b\u3001\u57fa\u5e95\u3068\u6b21\u5143\u3001\u7d14\u7c8b\u72b6\u614b\u304b\u6df7\u5408\u72b6\u614b\u304b\u3092\u305d\u308d\u3048\u307e\u3059\u3002\u305d\u306e\u3046\u3048\u3067\u3001\u76ee\u7684\u306b\u95a2\u4fc2\u3059\u308b\u6e2c\u5b9a\u306e\u4e88\u6e2c\u3084\u5225\u306e\u6307\u6a19\u3092\u4f75\u8a18\u3059\u308c\u3070\u3001\u540c\u3058\u6570\u5b57\u306e\u88cf\u306b\u3042\u308b\u9055\u3044\u3092\u8aad\u307f\u53d6\u308a\u3084\u3059\u304f\u306a\u308a\u307e\u3059\u3002<\/p>\n<p>\u4eca\u56de\u306e\u4f8b\u306f\u3001\u6b63\u898f\u5316\u3055\u308c\u305f\u7406\u60f3\u7684\u306a1\u91cf\u5b50\u30d3\u30c3\u30c8\u72b6\u614b\u306e\u4ee3\u6570\u8a08\u7b97\u3067\u3059\u3002QuTiP\u306e\u5b9f\u884c\u901f\u5ea6\u3084\u91cf\u5b50\u88c5\u7f6e\u306e\u6027\u80fd\u3092\u8a66\u9a13\u3057\u305f\u3082\u306e\u3067\u306f\u306a\u304f\u3001\u6e2c\u5b9a\u8aa4\u5dee\u3092\u542b\u3080\u5bc6\u5ea6\u884c\u5217\u306e\u63a8\u5b9a\u30fb\u4fee\u5fa9\u3082\u6271\u3063\u3066\u3044\u307e\u305b\u3093\u3002\u5fe0\u5b9f\u5ea6\u3068\u3044\u3046\u4e00\u3064\u306e\u5024\u304b\u3089\u3001\u72b6\u614b\u306e\u5168\u60c5\u5831\u3084\u5b9f\u7528\u4e0a\u306e\u512a\u52a3\u3092\u6c7a\u3081\u306a\u3044\u3053\u3068\u304c\u3001\u6bd4\u8f03\u306e\u51fa\u767a\u70b9\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<p>\u56f3\u8868\u30fb\u6570\u5024\u4f8b\u306f\u3001\u4e0a\u8a18\u306e\u5b9a\u7fa9\u306b\u5f93\u3063\u3066\u4f5c\u6210\u3057\u305f\u72ec\u81ea\u306e\u8aac\u660e\u3067\u3059\u3002<\/p>\n<h2>\u51fa\u5178<\/h2>\n<ol>\n<li><a href=\"https:\/\/qutip.readthedocs.io\/en\/qutip-5.1.x\/guide\/guide-states.html#density-matrices\">QuTiP 5.1 User Guide \u2014 States and operators \/ Density matrices<\/a>\u3002\u5bc6\u5ea6\u884c\u5217\u3068\u8ddd\u96e2\u6307\u6a19\u3001\u7d14\u7c8b\u72b6\u614b\u540c\u58eb\u306e\u95a2\u4fc2\u5f0f\u3092\u53c2\u7167\u30022026\u5e7410\u670816\u65e5UTC\u53d6\u5f97\u306e\u4fdd\u5b58\u7248\u3092\u4f7f\u7528\u3002<\/li>\n<li><a href=\"https:\/\/github.com\/qutip\/qutip\/blob\/7accc77a70a08f965a29fdd13515f79cdcab9703\/qutip\/core\/metrics.py\">QuTiP 5.1.1 \u2014 qutip\/core\/metrics.py<\/a>\u3002\u56fa\u5b9a\u30b3\u30df\u30c3\u30c8<code style=\"overflow-wrap:anywhere\">7accc77a70a08f965a29fdd13515f79cdcab9703<\/code>\u306e<code>fidelity<\/code>\u3068<code>tracedist<\/code>\u306e\u5b9a\u7fa9\u30fb\u5b9f\u88c5\u3092\u78ba\u8a8d\u3002\u30ac\u30a4\u30c9\u306e5.1\u7cfb\u30b9\u30ca\u30c3\u30d7\u30b7\u30e7\u30c3\u30c8\u3068\u56fa\u5b9a\u5b9f\u88c5\u3092\u533a\u5225\u3057\u3001\u6700\u65b0\u7248\u3067\u3042\u308b\u3068\u306f\u4e3b\u5f35\u3057\u3066\u3044\u307e\u305b\u3093\u3002<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"<p>\u91cf\u5b50\u72b6\u614b\u304c\u76ee\u6a19\u306b\u3069\u308c\u307b\u3069\u8fd1\u3044\u304b\u3092\u8868\u3059\u3068\u304d\u3001\u300c\u5fe0\u5b9f\u5ea6\u300d\u3068\u3044\u3046\u6570\u5024\u304c\u3088\u304f\u4f7f\u308f\u308c\u307e\u3059\u3002\u3057\u304b\u3057\u3001\u540c\u3058\u76ee\u6a19\u3078\u306e\u5fe0\u5b9f\u5ea6\u304c\u7b49\u3057\u304f\u3066\u3082\u3001\u72b6\u614b\u304c\u540c\u3058\u3068\u306f\u9650\u308a\u307e\u305b\u3093\u3002\u6e2c\u308a\u65b9\u3092\u5909\u3048\u308b\u3068\u3001\u4e00\u65b9\u3067\u306f\u51fa\u3084\u3059\u304f\u3001\u3082\u3046\u4e00\u65b9\u3067\u306f\u51fa\u306b\u304f\u3044\u7d50\u679c\u304c\u898b\u3064\u304b\u308b\u3053\u3068 [&hellip;]<\/p>\n","protected":false},"author":3,"featured_media":993,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":true,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":false,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[30],"tags":[184,274],"class_list":["post-995","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-computing","tag-quantum-computers","tag-quantum-state-fidelity"],"jetpack_publicize_connections":[],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"https:\/\/quantumsea.net\/wp-content\/uploads\/2026\/10\/qs-quantum-state-fidelity-trace-distance-20261017-featured-ca7b94ccde8f.png","_links":{"self":[{"href":"https:\/\/quantumsea.net\/index.php?rest_route=\/wp\/v2\/posts\/995","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/quantumsea.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/quantumsea.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/quantumsea.net\/index.php?rest_route=\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/quantumsea.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=995"}],"version-history":[{"count":1,"href":"https:\/\/quantumsea.net\/index.php?rest_route=\/wp\/v2\/posts\/995\/revisions"}],"predecessor-version":[{"id":996,"href":"https:\/\/quantumsea.net\/index.php?rest_route=\/wp\/v2\/posts\/995\/revisions\/996"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/quantumsea.net\/index.php?rest_route=\/wp\/v2\/media\/993"}],"wp:attachment":[{"href":"https:\/\/quantumsea.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=995"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/quantumsea.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=995"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/quantumsea.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=995"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}